A new photoelectrochemical system was fabricated by incorporating the cysteine or coenzyme A as electron donor into photoelectrochemical reaction of the nanostructured CdSe/ZnO photoelectrode to develop a photoelectrochemical method for the ultrasensitive determination of the cysteine and coenzyme A. The CdSe/ZnO photoelectrode was prepared by covering the CdSe quantum dots on the surface of ZnO nanorods arrays. The property of photoelectrode was investigated as photosensitive interface and electron acceptor, and its photoelectrochemical reaction was study with substrate. Under the 20 mW/cm² 410 nm visible light illuminations, the sensitive photocurrent response to the cysteine or coenzyme A was obtained at bias voltage 0 V. After the optimized experimental conditions, the photocurrent was proportional to the concentration of cysteine or the logarithm of coenzyme A concentration in the range of 1.00 × 10⁻²–20.0 μmol/L and 2.00 × 10⁻²–50.0 μmol/L, respectively. The detection sensitivity was 71.7 nA/μmol/L for cysteine. The detection limit was estimated to be 6.00 × 10⁻³ μmol/L (S/N = 3) and 1.00 × 10⁻² μmol/L (S/N = 3) for cysteine and coenzyme A, respectively. The other amino acids or common coenzymes were not interfering with the determination of cysteine and coenzyme A. Compared with other methods for the determination of cysteine and coenzyme A, the proposed method exhibits a wide measurement range, high sensitivity, and low cost.

通过将半胱氨酸或辅酶A作为电子供体引入纳米结构化CdSe / ZnO光电极的光电化学反应中，从而开发出一种用于半胱氨酸和辅酶A超灵敏测定的光电化学方法。覆盖了ZnO纳米棒阵列表面上的CdSe量子点。研究了光电极作为光敏界面和电子受体的性质，并研究了其与底物的光电化学反应。低于20 mW / cm ²在410 nm的可见光照射下，在0 V偏置电压下获得了对半胱氨酸或辅酶A的敏感光电流响应。在优化的实验条件下，光电流与半胱氨酸的浓度或辅酶A浓度的对数成正比，范围为1.00×10 ^-2 –20.0μmol/ L和2.00×10 ^-2 –50.0μmol/ L。对半胱氨酸的检测灵敏度为71.7 nA /μmol/ L。检测极限估计为6.00×10 ^-3 微摩尔/ L（S / N  = 3）和1.00×10 ^-2 微摩尔/ L（S / N = 3）分别代表半胱氨酸和辅酶A。其他氨基酸或常见的辅酶均不影响半胱氨酸和辅酶A的测定。与其他测定半胱氨酸和辅酶A的方法相比，该方法测量范围广，灵敏度高，成本低。