A photoelectrochemical (PEC) biosensor was constructed for 5-formylcytosine (5fC) nucleotide detection based on Ag₂S@WS₂ photoactive material and FeVO₄ catalytic signal quenching. After Ag₂S@WS₂ was modified onto the ITO substrate surface, 5fC recognition reagent of Au@4-amino3hydrazino5mercapto-1,2,4-triazol (Au@AHMT) was further modified through electrostatic adsorption. Afterwards, based on the specific chemical reaction between –NH₂ and –CHO, 5fC can be selectively recognized and captured. Subsequently, the nanoenzyme of FeVO₄ was recognized based on the specific reaction between the phosphate group of 5fC nucleotide and Fe³⁺. Under the catalysis of FeVO₄, the 4-chloro-1-naphthol in the detection solution can be oxidized to generate a precipitate, which will be retained on the electrode surface to inhibit the PEC signal. The developed method presented a widely dynamic range from 0.1 to 400 nM. The detection limit was 0.062 nM (3σ). This method also showed good detection selectivity, reproducibility and stability. The applicability was verified by investigating 5fC content change in genomic DNA of rice tissues after incubated with heavy metals. Moreover, the inhibited influence of hydrochar towards heavy metals was also assessed.

基于Ag ₂ S @ WS ₂光敏材料和FeVO ₄催化信号猝灭，构建了用于5-甲酰基胞嘧啶（5fC）核苷酸检测的光电化学（PEC）生物传感器。将Ag ₂ S @ WS ₂修饰到ITO衬底表面后，通过静电吸附进一步修饰Au4-氨基3-肼基5巯基-1,2,4-三唑的5fC识别试剂（Au @ AHMT）。然后，根据–NH ₂和–CHO之间的特定化学反应，可以选择性地识别和捕获5fC。随后，基于5fC核苷酸的磷酸基团与Fe ³⁺之间的特异性反应，识别出FeVO ₄的纳米酶。。在FeVO ₄的催化下，检测溶液中的4-氯-1-萘酚可被氧化生成沉淀物，该沉淀物将保留在电极表面以抑制PEC信号。所开发的方法具有0.1到400 nM的宽动态范围。检出限为0.062 nM（3σ）。该方法还显示出良好的检测选择性，重现性和稳定性。通过研究重金属孵育后水稻组织基因组DNA中5fC含量的变化，验证了其适用性。此外，还评估了炭黑对重金属的抑制作用。