Direct voltammetric sensing of L-cysteine at pristine GaN nanowires electrode.
The study demonstrates an electrochemical approach for direct sensing of L-Cysteine at gallium nitride nanowires (GaNNWs), a wide band gap semiconductor possessing 1-dimensional nanomaterial-specific high surface-sensitivity and unusually high surface-conductivity. Pristine GaNNWs can respond to L-Cysteine oxidation without any surface-modification: a unique advantage compared with other common electrodes. Cyclic voltammetric investigations on the effects of pH and potential-scan rate reveal an electrocatalytic oxidation of L-Cysteine controlled by the electroactive L-CyS(-) species. Advantages of direct L-Cysteine oxidation at surface-dominated GaNNWs electrodes can achieve an optimum sensitivity of 42 nA/μM with an experimental detection limit of 0.5 μM, over 0.5-75 μM dynamic range, under physiological condition (pH=7.4).
Lai
Yao-Tong
YT
Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106, Taiwan.
Ganguly
Abhijit
A
Chen
Li-Chyong
LC
Chen
Kuei-Hsien
KH
D015374:Biosensing Techniques / Q000379:methods* / Q000706:statistics & numerical data; D003545:Cysteine / Q000032:analysis*; D055664:Electrochemical Techniques; D004566:Electrodes; D005708:Gallium; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D053770:Nanowires / Q000648:ultrastructure; D010084:Oxidation-Reduction; D012680:Sensitivity and Specificity
C473348:gallium nitride; D005708:Gallium; D003545:Cysteine