A suitable electron donor, which guarantees the stability of the whole system, is considered as the driving force of the PEC sensor. Nowadays, searching appropriate electron donor is still one of the orientations to explorate in the field of sensor. Na₄₈[H₄₉₆Mo₃₆₈O₁₄₆₄S₄₈]·ca.1000H₂O (abbr. {Mo₃₆₈}), as a type of polyoxometalate, has perfect morphology, definite size and unique electronic property. Due to the prominent water solubility, {Mo₃₆₈} usually releases small cations and exists as large anions in the ultrapure water. The interesting property endows {Mo₃₆₈} with excellent reducibility, which provides great feasibility to become an outstanding electron donor. In addition, FeOOH prepared through a simple operation owns high adsorption capacity, which ensures the fastness of other materials. Subsequently, the narrow band-gap of Bi₂S₃ and the unique noble metal properties of Au nanoparticles are utilized to co-sensitize FeOOH to improve the light-harvesting capability and photoelectric conversion efficiency. Combined with the specificity recognition of antigen and antibody, a novel photoelectrochemical sensor is constructed with a wide detection range of 1.00 pg mL⁻¹ - 100 ng mL⁻¹ and low detection limit (0.76 pg mL⁻¹), which achieves the sensitive detection of cardiac troponin I in early diagnosis of cardiovascular disease.

保证整个系统稳定性的合适电子供体被认为是PEC传感器的驱动力。如今，寻找合适的电子供体仍然是传感器领域探索的方向之一。Na ₄₈ [H ₄₉₆ Mo ₃₆₈ O ₁₄₆₄ S ₄₈ ]·约1000H ₂ O（缩写为{Mo ₃₆₈ }），作为一种多金属氧酸盐，具有完美的形貌，确定的尺寸和独特的电子性能。由于突出的水溶性，{Mo ₃₆₈ }通常释放出小的阳离子，并以超大的阴离子形式存在于超纯水中。有趣的财产赋予{Mo ₃₆₈}具有出色的还原性，这为成为出色的电子供体提供了极大的可行性。另外，通过简单的操作制备的FeOOH具有很高的吸附能力，从而确保了其他材料的牢度。随后，利用Bi ₂ S ₃的窄带隙和Au纳米粒子的独特贵金属特性来共敏化FeOOH，以提高光收集能力和光电转换效率。结合抗原和抗体的特异性识别，构建了一种新型的光电化学传感器，其检测范围为1.00 pg mL ^-1-100 ng mL ^-1，检测限低（0.76 pg mL ^-1），可在心血管疾病的早期诊断中灵敏地检测出心肌肌钙蛋白I。