Chen Yafei, Zhang Xuhui, Huang Wanjin, Jin Zhenhuan, Wei Xiaoping, Li Jianping
Guangxi Key Laboratory of Electrochemical and Magnetochemical Function Materials, College of Chemistry and Bioengineering, Guilin University of Technology, Guilin, 541004, Guangxi, China.
Mikrochim Acta. 2025 May 27;192(6):376. doi: 10.1007/s00604-025-07231-9.
Atrazine (ATZ) is used extensively, resulting in residues in food and the environment, posing a serious threat to human health. Herein, CdZnS/TiC photoelectric material was synthesized and immobilized on a FTO electrode as a photoanode. A photoelectrochemical (PEC) aptamer sensor was constructed for the highly sensitive and selective determination of ATZ based on signal amplification via cascade catalysis of CRISPR/Cas12a and G-quadruplex/hemin DNAzyme (G4/hemin DNAzyme). G4/hemin DNAzyme catalyses the oxidation reaction between HO and dopamine (DA) to form polydopamine (PDA) deposit. This process, in turn, inhibits the photocurrent at the photoanode, leading to a decrease in photocurrent. Concurrently, the depletion of DA as an electron donor for the PEC reaction at the photoelectrode further contributes to the decrease in photocurrent. ATZ can hybridize with ATZ aptamer (Apt) in Apt/cDNA to release activation strand (cDNA), which activates the activity of CRISPR/Cas12a and triggers cleavage of G4, causing the cleaving of G4/hemin DNAzyme immobilized on the electrode surface. This process leads to a decrease of G4/hemin DNAzymes amount on the electrode, consequently reducing both the PDA generation and the DA consumption. As a result, the photocurrent is restored. The cascade catalysis of CRISPR/Cas12a and G4/hemin DNAzyme has been demonstrated to result in photocurrent amplification. The photocurrent change was linear with the logarithmic value of ATZ concentration in the range 1.00 × 10 to 1.00 × 10 mol/L. The limit of detection was 3.47 × 10 mol/L. The sensor has been successfully applied to the determination of trace ATZ in environmental and food samples.
莠去津（ATZ）被广泛使用，导致其在食品和环境中残留，对人类健康构成严重威胁。在此，合成了CdZnS/TiC光电材料并将其固定在FTO电极上作为光阳极。构建了一种光电化学（PEC）适体传感器，用于基于CRISPR/Cas12a和G-四链体/血红素DNAzyme（G4/血红素DNAzyme）的级联催化信号放大来高灵敏且选择性地测定ATZ。G4/血红素DNAzyme催化HO与多巴胺（DA）之间的氧化反应形成聚多巴胺（PDA）沉积物。这个过程反过来会抑制光阳极处的光电流，导致光电流降低。同时，作为光电极PEC反应电子供体的DA的消耗进一步导致光电流降低。ATZ可以与Apt/cDNA中的ATZ适体（Apt）杂交以释放激活链（cDNA），从而激活CRISPR/Cas12a的活性并触发G4的切割，导致固定在电极表面的G4/血红素DNAzyme的切割。这个过程导致电极上G4/血红素DNAzyme的量减少，从而减少PDA的生成和DA的消耗。结果，光电流得以恢复。已证明CRISPR/Cas12a和G4/血红素DNAzyme的级联催化会导致光电流放大。光电流变化与1.00×10至1.00×10 mol/L范围内的ATZ浓度的对数值呈线性关系。检测限为3.47×10 mol/L。该传感器已成功应用于环境和食品样品中痕量ATZ的测定。
