Corresponding Author

Lan-Qun Mao(lqmao@iccas.ac.cn)


Brain, as the source of neural activities such as perceptions and emotions, consists of the dynamic and complex networks of neurons that implement brain functions through electrical and chemical interactions. Therefore, analyzing and monitoring neurochemicals in living brain can greatly contribute to uncovering the molecular mechanism in both physiological and pathological processes, and to taking a further step in developing precise medical diagnosis and treatment against brain diseases. Through collaborations across disciplines, a handful of analytical tools have been proven to be befitting in neurochemical measurement, spanning the level of vesicles, cells, and living brains. Among these, electrochemical methods endowed with high sensitivity and spatiotemporal resolution provide a promising way to precisely describe the dynamics of target neurochemicals during various neural activities. In this review, we expand the discussion on strategies to address two key issues of in vivo electrochemical sensing, namely, selectivity and biocompatibility, taking our latest studies as typical examples. We systematically elaborate for the first time the rationale behind engineering electrode/brain interface, as well as the unique advantages of potentiometric sensing methods. In particular, we highlight our recent progress on employing the as-prepared in vivo electrochemical sensors to unravel the molecular mechanism of ascorbate in physiological and pathological processes, aiming to draw a blueprint for the future development of in vivo electrochemical sensing of brain neurochemicals.

Graphical Abstract


in vivo electrochemical sensing, brain chemistry, selectivity, biocompatibility

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[1] Bruns D, Jahn R. Real-time measurement of transmitter release from single synaptic vesicles[J]. Nature, 1995, 377(6544):62-65.
doi: 10.1038/377062a0 URL

[2] Gao R X, Asano S M, Upadhyayula S, Pisarev I, Milkie D E, Liu T L, Singh V, Graves A, Huynh G H, Zhao Y X, Bogovic J, Colonell J, Ott C M, Zugates C, Tappan S, Rodriguez A, Mosaliganti K R, Sheu S H, Pasolli H A, Pang S, Xu C S, Megason S G, Hess H, Lippincott-Schw-artz J, Hantman A, Rubin G M, Kirchhausen T, Saalfeld S, Aso Y, Boydent E S, Betzig E. Cortical column and whole-brain imaging with molecular contrast and nanoscale resolution[J]. Science, 2019, 363(6424):245.

[3] Mohebi A, Pettibone J R, Hamid A A, Wong J M T, Vinson L T, Patriarchi T, Tian, L, Kennedy R T, Berke J D. Dissociable dopamine dynamics for learning and motivation[J]. Nature, 2019, 570(7759):65-70.
doi: 10.1038/s41586-019-1235-y URL

[4] Cserep C, Posfai B, Lenart N, Fekete R, Laszlo Z I, Lele Z, Orsolits B, Molnar G, Heindl S, Schwarcz A D, Ujvari K, Kornyei Z, Toth K, Szabadits E, Sperlagh B, Baranyi M, Csiba L, Hortobagyi T, Magloczky Z, Martinecz B, Szabo G, Erdelyi F, Szipocs R, Tamkun M M, Gesierich B, Duering M, Katona I, Liesz A, Tamas G, Denes A. Microglia monitor and protect neuronal function through specialized somatic purinergic junctions[J]. Science, 2020, 367(6477):528.
doi: 10.1126/science.aax6752 URL

[5] Phan N, Li X C, Ewing A G. Measuring synaptic vesicles using cellular electrochemistry and nanoscale molecular imaging[J]. Nat. Rev. Chem., 2017, 1(6):0048.
doi: 10.1038/s41570-017-0048 URL

[6] Wu F, Yu P, Mao L Q. Analytical and quantitative in vivo monitoring of brain neurochemistry by electrochemical and imaging approaches[J]. ACS Omega, 2018, 3(10):13267-13274.
doi: 10.1021/acsomega.8b02055 URL

[7] Liu Z C, Tian Y. Recent advances in development of devices and probes for sensing and imaging in the brain[J]. Sci. China-Chem., 2021, 64(6):915-931.
doi: 10.1007/s11426-020-9961-3 URL

[8] Ding C Q, Zhu A W, Tian Y. Functional surface engineering of C-dots for fluorescent biosensing and in vivo bioimaging[J]. Acc. Chem. Res., 2014, 47(1):20-30.
doi: 10.1021/ar400023s URL

[9] Patriarchi T, Cho J R, Merten K, Howe M W, Marley A, Xiong W H, Folk R W, Broussard G J, Liang R, Jang M J, Zhong H, Dombeck D, von Zastrow M, Nimmerjahn A, Gradinaru V, Williams J T, Tian L. Ultrafast neuronal imaging of dopamine dynamics with designed genetically encoded sensors[J]. Science, 2018, 360(6396):1420.

[10] Sun F M, Zeng J Z, Jing M, Zhou J H, Feng J S, Owen S F, Luo Y C, Li F N, Wang H, Yamaguchi T, Yong Z H, Gao Y J, Peng W L, Wang L Z, Zhang S Y, Du J L, Lin D Y, Xu M, Kreitzer A C, Cui G H, Li Y L. A genetically encoded fluorescent sensor enables rapid and specific detection of dopamine in flies, fish, and mice[J]. Cell, 2018, 174(2):481-496.
doi: 10.1016/j.cell.2018.06.042 URL

[11] Tonnesen J, Inavalli V, Nagerl U V. Super-resolution imaging of the extracellular space in living brain tissue[J]. Cell, 2018, 172(5):1108-1121.
doi: 10.1016/j.cell.2018.02.007

[12] Villette V, Chavarha M, Dimov I K, Bradley J, Pradhan L, Mathieu B, Evans S W, Chamberland S, Shi D Q, Yang R Z, Kim B B, Ayon A, Jalil A, St-Pierre F, Schnitzer M J, Bi G Q, Toth K, Ding J, Dieudonne S, Lin M Z. Ultrafast two-photon imaging of a high-gain voltage indicator in awake behaving mice[J]. Cell, 2019, 179(7):1590-1608.
doi: S0092-8674(19)31225-5 pmid: 31835034

[13] Robinson D L, Hermans A, Seipel A T, Wightman R M. Monitoring rapid chemical communication in the brain[J]. Chem. Rev., 2008, 108(7):2554-2584.
doi: 10.1021/cr068081q pmid: 18576692

[14] Wilson G S, Johnson M A. In-vivo electrochemistry: What can we learn about living systems?[J]. Chem. Rev., 2008, 108(7):2462-2481.
doi: 10.1021/cr068082i URL

[15] Wang W, Zhang S H, Li L M, Wang Z L, Cheng J K, Huang W H. Monitoring of vesicular exocytosis from single cells using micrometer and nanometer-sized electrochemical sensors[J]. Anal. Bioanal. Chem., 2009, 394(1):17-32.
doi: 10.1007/s00216-009-2703-2 pmid: 19274456

[16] Bucher E S, Wightman R M. Electrochemical analysis of neurotransmitters[J]. Annu. Rev. Anal. Chem., 2015, 8(1):239-261.
doi: 10.1146/annurev-anchem-071114-040426 URL

[17] Xue Y F, Xiao T F, Jiang Y N, Wu F, Yu P, Mao L Q. Progress of in vivo electrochemical analysis of brain neurochemistry[J]. Chinese J. Anal. Chem., 2019, 47(10):1443-1454.

[18] Song E M, Li J H, Won S M, Bai W B, Rogers J A. Materials for flexible bioelectronic systems as chronic neural interfaces[J]. Nat. Mater., 2020, 19(6):590-603.
doi: 10.1038/s41563-020-0679-7 URL

[19] Rodeberg N T, Sandberg S G, Johnson J A, Phillips P E M, Wightman R M. Hitchhiker’s guide to voltammetry: acute and chronic electrodes for in vivo fast-scan cyclic voltammetry[J]. ACS Chem. Neurosci., 2017, 8(2):221-234.
doi: 10.1021/acschemneuro.6b00393 pmid: 28127962

[20] Roberts J G, Sombers L A. Fast-scan cyclic voltammetry: chemical sensing in the brain and beyond[J]. Anal. Chem., 2018, 90(1):490-504.
doi: 10.1021/acs.analchem.7b04732 pmid: 29182309

[21] Puthongkham P, Venton B J. Recent advances in fast-scan cyclic voltammetry[J]. Analyst, 2020, 145(4):1087-102.
doi: 10.1039/c9an01925a pmid: 31922162

[22] Heien M, Khan A S, Ariansen J L, Cheer J F, Phillips P E M, Wassum K M, Wightman R M. Real-time measurement of dopamine fluctuations after cocaine in brain of behaving rats[J]. Proc. Natl. Acad. Sci. U.S.A., 2005, 102(29):10023-10028.
doi: 10.1073/pnas.0504657102 URL

[23] Xu J C, Qin G G, Luo F, Wang L N, Zhao R, Li N, Yuan J H, Fang X H. Automated stoichiometry analysis of single-molecule fluorescence imaging traces via deep learning[J]. J. Am. Chem. Soc., 2019, 141(17):6979-6985.

[24] Falk T, Mai D, Bensch R, Cicek O, Abdulkadir A, Marrakchi Y, Boehm A, Deubner J, Jaeckel Z, Seiwald K, Dovzhenko A, Tietz O, Dal Bosco C, Walsh S, Saltukoglu D, Tay T L, Prinz M, Palme K, Simons M, Diester I, Brox T, Ronneberger O. U-Net: deep learning for cell counting, detection, and morphometry[J]. Nat. Methods, 2019, 16(1):67-70.

[25] Wang H D, Rivenson Y, Jin Y Y, Wei Z S, Gao R, Gunaydin H, Bentolila L A, Kural C, Ozcan A. Deep learning enables cross-modality super-resolution in fluorescence microscopy[J]. Nat. Methods, 2019, 16(1):103-110.
doi: 10.1038/s41592-018-0239-0 URL

[26] Xue Y F, Ji W L, Jiang Y N, Yu P, Mao L Q. Deep learning for voltammetric sensing in a living animal brain[J]. Angew. Chem. Int. Ed., 2021, 60(44):23777-23783.
doi: 10.1002/anie.202109170 URL

[27] Zhang M N, Yu P, Mao L Q. Rational design of surface/interface chemistry for quantitative in vivo monitoring of brain chemistry[J]. Acc. Chem. Res., 2012, 45(4):533-543.
doi: 10.1021/ar200196h URL

[28] Wu F, Yu P, Mao L Q. Bioelectrochemistry for in vivo analysis: Interface engineering toward implantable electrochemical biosensors[J]. Curr. Opin. Electrochem., 2017, 5(1):152-157.

[29] Zhan L M, Tian Y. Designing recognition molecules and tailoring functional surfaces for in vivo monitoring of small molecules in the brain[J]. Acc. Chem. Res., 2018, 51(3):688-696.
doi: 10.1021/acs.accounts.7b00543 URL

[30] Lin Y Q, Liu K, Yu P, Xiang L, Li X C, Mao L Q. A facile electrochemical method for simultaneous and on-line measurements of glucose and lactate in brain microdialysate with prussian blue as the electrocatalyst for reduction of hydrogen peroxide[J]. Anal. Chem., 2007, 79(24):9577-9583.
doi: 10.1021/ac070966u URL

[31] Lin Y Q, Zhu N N, Yu P, Su L, Mao L Q. Physiologically relevant online electrochemical method for continuous and simultaneous monitoring of striatum glucose and lactate following global cerebral ischemia/reperfusion[J]. Anal. Chem., 2009, 81(6):2067-2074.
doi: 10.1021/ac801946s URL

[32] Huang P C, Mao J J, Yang L F, Yu P, Mao L Q. Bioelectrochemically active infinite coordination polymer nanoparticles: one-pot synjournal and biosensing property[J]. Chem. - Eur. J., 2011, 17(41):11390-11393.
doi: 10.1002/chem.201101634 URL

[33] Zhuang X M, Wang D L, Lin Y Q, Yang L F, Yu P, Jiang W, Mao L Q. Strong interaction between imidazolium-based polycationic polymer and ferricyanide: toward redox potential regulation for selective in vivo electrochemical measurements[J]. Anal. Chem., 2012, 84(4):1900-1906.
doi: 10.1021/ac202748s URL

[34] Lu X L, Cheng H J, Huang P C, Yang L F, Yu P, Mao L Q. Hybridization of bioelectrochemically functional infinite coordination polymer nanoparticles with carbon nanotubes for highly sensitive and selective in vivo electrochemical monitoring[J]. Anal. Chem., 2013, 85(8):4007-4013.
doi: 10.1021/ac303743a URL

[35] Ma W J, Jiang Q, Yu P, Yang L F, Mao L Q. Zeolitic imidazolate framework-based electrochemical biosensor for in vivo electrochemical measurements[J]. Anal. Chem., 2013, 85(15):7550-7557.
doi: 10.1021/ac401576u URL

[36] Lin Y Q, Yu P, Hao J, Wang Y X, Ohsaka T, Mao L Q. Continuous and simultaneous electrochemical measurements of glucose, lactate, and ascorbate in rat brain following brain ischemia[J]. Anal. Chem., 2014, 86(8):3895-3901.
doi: 10.1021/ac4042087 URL

[37] Zhang Z P, Hao J, Xiao T F, Yu P, Mao L Q. Online ele-ctrochemical systems for continuous neurochemical measurements with low-potential mediator-based electroche-mical biosensors as selective detectors[J]. Analyst, 2015, 140(15):5039-5047.
doi: 10.1039/C5AN00593K URL

[38] Wang Y X, Mao L. Recent advances in analytical metho-dology for in vivo electrochemistry in mammals[J]. Electroanalysis, 2016, 28(2):265-276.
doi: 10.1002/elan.201500376 URL

[39] Xiao T F, Wu F, Hao J, Zhang M N, Yu P, Mao L Q. In vivo analysis with electrochemical sensors and biosensors[J]. Anal. Chem., 2017, 89(1):300-313.
doi: 10.1021/acs.analchem.6b04308 URL

[40] Wei H, Wu F, Yu P, Mao L Q. Advances in electrochemical biosensors for in vivo analysis[J]. Chinese J. Anal. Chem., 2019, 47(10):1466-1479.

[41] Xu C, Wu F, Yu P, Mao L Q. In vivo electrochemical sensors for neurochemicals: recent update[J]. ACS Sens., 2019, 4(12):3102-3118.
doi: 10.1021/acssensors.9b01713 URL

[42] Pan C, Wei H, Han Z J, Wu F, Mao L Q. Enzymatic electrochemical biosensors for in situ neurochemical measurement[J]. Curr. Opin. Electrochem., 2020, 19:162-167.

[43] Wu F, Yu P, Yang X T, Han Z J, Wang M, Mao L Q. Exploring ferredoxin-dependent glutamate synthase as an enzymatic bioelectrocatalyst[J]. J. Am. Chem. Soc., 2018, 140(40):12700-12704.
doi: 10.1021/jacs.8b08020 URL

[44] Dunn M R, Jimenez R M, Chaput J C. Analysis of aptamer discovery and technology[J]. Nat. Rev. Chem., 2017, 1(10):0076.
doi: 10.1038/s41570-017-0076 URL

[45] Yu P, He X L, Zhang L, Mao L Q. Dual recognition unit strategy improves the specificity of the Adenosine Triphosphate (ATP) aptamer biosensor for cerebral ATP assay[J]. Anal. Chem., 2015, 87(2):1373-1380.
doi: 10.1021/ac504249k URL

[46] Hou H F, Jin Y, Wei H, Ji W L, Xue Y F, Hu J B, Zhang M N, Jiang Y, Mao L Q. A generalizable and noncovalent strategy for interfacing aptamers with a microelectrode for the selective sensing of neurotransmitters in vivo[J]. Angew. Chem., Int. Ed., 2020, 59(43):18996-19000.
doi: 10.1002/anie.202008284 URL

[47] Zhao X, Wang K Q, Li B, Li C Q, Lin Y Q. Preparation, surface modification and in vivo/single cell electroanalytical application of microelectrode[J]. Prog. Chem., 2017, 29(10):1173-1183.
doi: 10.7536/PC170620

[48] Hu K K, Liu Y L, Oleinick A, Mirkin M V, Huang W H, Amatore C. Nanoelectrodes for intracellular measurements of reactive oxygen and nitrogen species in single living cells[J]. Curr. Opin. Electrochem., 2020, 22:44-50.

[49] Cheng S W, Zhang L, Zhang M N. In vivo detection of hydrogen sulfide in brain and cell[J]. Electroanalysis, 2021, 33:1-15.
doi: 10.1002/elan.202060235 URL

[50] Cheng H J, Li L J, Zhang M N, Jiang Y, Yu P, Ma F R, Mao L Q. Recent advances on in vivo analysis of ascorbic acid in brain functions[J]. Trac-Trends Anal. Chem., 2018, 109:247-259.
doi: 10.1016/j.trac.2018.10.017 URL

[51] Ji W L, Zhang M N, Mao L Q. Recent advances on in vivo electrochemical analysis of Vitamin C in rat brain[J]. Chinese J. Anal. Chem., 2019, 47(10):1559-1571.

[52] Rebec G V, Centore J M, White L K, Alloway K D. Ascorbic-acid and the behavioral-response to haloperidol -implications for the action of antipsychotic-drugs[J]. Science, 1985, 227(4685):438-440.
pmid: 4038426

[53] Rice M E. Ascorbate regulation and its neuroprotective role in the brain[J]. Trends Neurosci., 2000, 23(5):209-216.
pmid: 10782126

[54] Zhang M N, Liu K, Gong K P, Su L, Chen Y, Mao L Q. Continuous on-line monitoring of extracellular ascorbate depletion in the rat striatum induced by global ischemia with carbon nanotube-modified glassy carbon electrode integrated into a thin-layer radial flow cell[J]. Anal. Chem., 2005, 77(19):6234-6242.
doi: 10.1021/ac051188d URL

[55] Zhang M N, Liu K, Xiang L, Lin Y Q, Su L, Mao L Q. Carbon nanotube-modified carbon fiber microelectrodes for in vivo voltammetric measurement of ascorbic acid in rat brain[J]. Anal. Chem., 2007, 79(17):6559-6565.
doi: 10.1021/ac0705871 URL

[56] Xiang L, Yu P, Hao J, Zhang M N, Zhu L, Dai L M, Mao L Q. Vertically aligned carbon nanotube-sheathed carbon fibers as pristine microelectrodes for selective monitoring of ascorbate in vivo[J]. Anal. Chem., 2014, 86(8):3909-3914.
doi: 10.1021/ac404232h pmid: 24678660

[57] Xiao T F, Jiang Y N, Ji W L, Mao L Q. Controllable and reproducible sheath of carbon fibers with single-walled carbon nanotubes through electrophoretic deposition for in vivo electrochemical measurements[J]. Anal. Chem., 2018, 90(7):4840-4846.
doi: 10.1021/acs.analchem.8b00303 URL

[58] Cui X J, Li W, Ryabchuk P, Junge K, Beller M. Bridging homogeneous and heterogeneous catalysis by heterogeneous single-metal-site catalysts[J]. Nat. Catal., 2018, 1(6):385-397.
doi: 10.1038/s41929-018-0090-9 URL

[59] Wang A Q, Li J, Zhang T. Heterogeneous single-atom catalysis[J]. Nat. Rev. Chem., 2018, 2(6):65-81.
doi: 10.1038/s41570-018-0010-1 URL

[60] Wu F, Pan C, He C T, Han Y H, Ma W J, Wei H, Ji W L, Chen W X, Mao J J, Yu P, Wang D S, Mao L Q, Li Y D. Single-atom Co-N4 Electrocatalyst enabling four-electron oxygen reduction with enhanced hydrogen peroxide tolerance for selective sensing[J]. J. Am. Chem. Soc., 2020, 142(39):16861-16867.
doi: 10.1021/jacs.0c07790 URL

[61] Zhou M, Jiang Y, Wang G, Wu W J, Chen W X, Yu P, Lin Y Q, Mao J J, Mao L Q. Single-atom Ni-N4 provides a robust cellular NO sensor[J]. Nat. Commun., 2020, 11(1):3188.
doi: 10.1038/s41467-020-17018-6 pmid: 32581225

[62] Hou H F, Mao J J, Han Y H, Wu F, Zhang M N, Wang D S, Mao L Q, Li Y D. Single-atom electrocatalysis: a new approach to in vivo electrochemical biosensing[J]. Sci. China-Chem., 2019, 62(12):1720-1724.
doi: 10.1007/s11426-019-9605-0 URL

[63] Guo S Y, Yan H L, Wu F, Zhao L J, Yu P, Liu H B, Li Y L, Mao L Q. Graphdiyne as electrode material: tuning electronic state and surface chemistry for improved electrode reactivity[J]. Anal. Chem., 2017, 89(23):13008-13015.
doi: 10.1021/acs.analchem.7b04115 URL

[64] Qi H T, Yu P, Wang Y X, Han G C, Liu H B, Yi Y P, Li Y L, Mao L Q. Graphdiyne oxides as excellent substrate for electroless deposition of Pd clusters with high catalytic activity[J]. J. Am. Chem. Soc., 2015, 137(16):5260-5263.
doi: 10.1021/ja5131337 URL

[65] Yan H L, Yu P, Han G C, Zhang Q H, Gu L P, Yi Y P, Liu H B, Li Y L, Mao L Q. High-yield and damage-free exfoliation of layered Graphdiyne in aqueous phase[J]. Angew. Chem. Int. Ed., 2019, 58(3):746-750.
doi: 10.1002/anie.201809730 URL

[66] Yan H L, Guo S Y, Wu F, Yu P, Liu H B, Li Y L, Mao L Q. Carbon atom hybridization matters: ultrafast humidity response of Graphdiyne oxides[J]. Angew. Chem. Int. Ed., 2018, 57(15):3922-3926.
doi: 10.1002/anie.201709417 URL

[67] Guo S Y, Yu P, Li W Q, Yi Y P, Wu F, Mao L Q. Electron hopping by interfacing semiconducting Graphdiyne nanosheets and redox molecules for selective electrocatalysis[J]. J. Am. Chem. Soc., 2020, 142(4):2074-2082.
doi: 10.1021/jacs.9b13678 URL

[68] Yu P, He X L, Mao L Q. Tuning interionic interaction for highly selective in vivo analysis[J]. Chem. Soc. Rev., 2015, 44(17):5959-5968.
doi: 10.1039/C5CS00082C URL

[69] He X L, Zhang K L, Li T, Jiang Y N, Yu P, Mao L Q. Micrometer-Scale ion current rectification at Polyelectrolyte brush-modified micropipets[J]. J. Am. Chem. Soc., 2017, 139(4):1396-1399.
doi: 10.1021/jacs.6b11696 URL

[70] He X L, Zhang K L, Liu Y, Wu F, Yu P, Mao L Q. Chao-tropic monovalent anion-induced rectification inversion at nanopipettes modified by polyimidazolium brushes[J]. Angew. Chem. Int. Ed., 2018, 57(17):4590-4593.
doi: 10.1002/anie.201800335 URL

[71] Zhang K L, He X L, Liu Y, Yu P, Fei J J, Mao L Q. Highly selective cerebral ATP assay based on micrometer scale ion current rectification at Polyimidazolium-modified micropipettes[J]. Anal. Chem., 2017, 89(12):6794-6799.
doi: 10.1021/acs.analchem.7b01218 URL

[72] Zhang K L, Wei H, Xiong T Y, Jiang Y N, Ma W J, Wu F, Yu P, Mao L Q. Micrometer-scale transient ion transport for real-time pH assay in living rat brains[J]. Chem. Sci., 2021, 12(21):7369-7376.
doi: 10.1039/D1SC00061F URL

[73] Hefti F, Felix D. Chronoamperometry in vivo - Does it interfere with spontaneous neuronal-activity in the brain[J]. J. Neurosci. Methods, 1983, 7(2):151-156.
doi: 10.1016/0165-0270(83)90077-8 URL

[74] Zhao L J, Zheng W, Mao L Q. Recent advances of ion-selective electrode for in vivo analysis in brain neurochemistry[J]. Chinese J. Anal. Chem., 2019, 47(10):1480-1491.[75] Hao J, Xiao T F, Wu F, Yu P, Mao L Q. High antifouling property of ion-selective membrane: toward in vivo monitoring of pH change in live brain of rats with membrane-coated carbon fiber electrodes[J]. Anal. Chem., 2016, 88(22):11238-11243.
doi: 10.1021/acs.analchem.6b03854 URL

[76] Zhao L J, Jiang Y N, Hao J, Wei H, Zheng W, Mao L Q. Graphdiyne oxide enhances the stability of solid contact-based ionselective electrodes for excellent in vivo analysis[J]. Sci. China-Chem., 2019, 62(10):1414-1420.
doi: 10.1007/s11426-019-9516-5 URL

[77] Zhao L J, Jiang Y, Wei H, Jiang Y N, Ma W J, Zheng W, Cao A M, Mao L Q. In vivo measurement of calcium ion with solid-state ion-selective electrode by using shelled hollow carbon nanospheres as a transducing layer[J]. Anal. Chem., 2019, 91(7):4421-4428.
doi: 10.1021/acs.analchem.8b04944

[78] Wu F, Yu P, Mao L. Self-powered electrochemical systems as neurochemical sensors: toward self-triggered in vivo analysis of brain chemistry[J]. Chem. Soc. Rev., 2017, 46(10):2692-2704.
doi: 10.1039/C7CS00148G URL

[79] Wu F, Su L, Yu P, Mao L Q. Role of organic solvents in immobilizing fungus laccase on single-walled carbon nanotubes for improved current response in direct bioelectrocatalysis[J]. J. Am. Chem. Soc., 2017, 139(4):1565-1574.
doi: 10.1021/jacs.6b11469 URL

[80] Wu F, Cheng H J, Wei H, Xiong T Y, Yu P, Mao L Q. Galvanic redox potentiometry for self-driven in vivo measurement of neurochemical dynamics at open-circuit potential[J]. Anal. Chem., 2018, 90(21):13021-13029.
doi: 10.1021/acs.analchem.8b03854 URL

[81] Yu P, Wei H, Zhong P P, Xue Y F, Wu F, Liu Y, Fei J J, Mao L Q. Single-carbon-fiber-powered microsensor for in vivo neurochemical sensing with high neuronal compatibility[J]. Angew. Chem. Int. Ed., 2020, 59(50):22652-22658.
doi: 10.1002/anie.202010195 URL

[82] Yue Q W, Li X C, Wu F, Ji W L, Zhang Y, Yu P, Zhang M N, Ma W J, Wang M, Mao L Q. Unveiling the role of DJ-1 protein in vesicular storage and release of catechola-mine with nano/micro-tip electrodes[J]. Angew. Chem. Int. Ed., 2020, 59(27):11061-11065.
doi: 10.1002/anie.202002455 URL

[83] Zhang Z P, Zhao L Z, Lin Y Q, Yu P, Mao L Q. Online electrochemical measurements of Ca2+ and Mg2+ in rat brain based on divalent cation enhancement toward electrocatalytic NADH oxidation[J]. Anal. Chem., 2010, 82(23):9885-9891.
doi: 10.1021/ac102605n URL

[84] Xiao T F, Wang Y X, Wei H, Yu P, Jiang Y, Mao L Q. Electrochemical monitoring of propagative fluctuation of ascorbate in the live rat brain during spreading depolarization[J]. Angew. Chem. Int. Ed., 2019, 58(20):6616-6619.
doi: 10.1002/anie.201901035 URL

[85] Jin J, Ji W L, Li L J, Zhao G, Wu W J, Wei H, Ma F R, Jiang Y, Mao L Q. Electrochemically probing dynamics of ascorbate during cytotoxic edema in living rat brain[J]. J. Am. Chem. Soc., 2020, 142(45):19012-19016.
doi: 10.1021/jacs.0c09011 URL

[86] Wang K, Xiao T F, Yue Q W, Wu F, Yu P, Mao L Q. Selective amperometric recording of endogenous ascorbate secretion from a single rat adrenal chromaffin cell with pretreated carbon fiber microelectrodes[J]. Anal. Chem., 2017, 89(17):9502-9507.
doi: 10.1021/acs.analchem.7b02508 pmid: 28776368

[87] Zhang N, Liu J X, Ma F R, Yu L S, Lin Y Q, Liu K, Mao L Q. Change of extracellular ascorbic acid in the brain cortex following ice water vestibular stimulation: an on-line electrochemical detection coupled with in vivo microdialysis sampling for guinea pigs[J]. Chin. Med. J., 2008, 121(12):1120-1125.
doi: 10.1097/00029330-200806020-00016 URL

[88] Liu J X, Yu P, Lin Y Q, Zhou N, Li T, Ma F R, Mao L Q. In vivo electrochemical monitoring of the change of cochlear perilymph ascorbate during salicylate-induced tinnitus[J]. Anal. Chem., 2012, 84(12):5433-5438.
doi: 10.1021/ac301087v URL

[89] Lyu Y, Zhang Y W, Tan L, Ji W L, Yu P, Mao L Q, Zhou F. Continuously monitoring of concentration of extracellular ascorbic acid in spinal cord injury model[J]. Chinese J. Anal. Chem., 2017, 45(11):1595-1599.

[90] Xin Y, Song Y, Xiao T F, Zhang Y H, Li L J, Li T, Zhang K, Liu J X, Ma F R, Mao L Q. In vivo recording of ascorbate and neural excitability in medial vestibular nucleus and hippocampus following ice water vestibular stimulation in rats[J]. Electroanalysis, 2018, 30(7):1287-1292.
doi: 10.1002/elan.201800187 URL

[91] Zhang Y W, Hou G J, Ji W L, Rao F, Zhou R B, Gao S, Mao L Q, Zhou F. Persistent oppression and simple decompression both exacerbate spinal cord ascorbate levels[J]. Int. J. Med. Sci., 2020, 17(9):1167-1176.
doi: 10.7150/ijms.41289 URL

[92] Wang M L, Song Y, Liu J X, Du Y L, Xiong S, Fan X, Wang J, Zhang Z D, Mao L Q, Ma F R. Role of the caudate-putamen n



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