Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, 410081, China.
Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, 410081, China.
Talanta. 2022 Nov 1;249:123660. doi: 10.1016/j.talanta.2022.123660. Epub 2022 Jun 4.
We report here Au nanoparticles (AuNPs)/SnS/ZnInS as a high-performance active material for sensitive photoelectrochemical (PEC) determination of T4 polynucleotide kinase (T4 PNK) using an enzymatic reaction-induced DNA structure switch strategy. To construct the PEC biosensor, a double-stranded DNA probe consisting of a CdS quantum dots (QDs)-labeled single-stranded DNA (sDNA) and its complementary DNA (cDNA) is immobilized on the AuNPs/SnS/ZnInS photoactive material. T4 PNK can catalyze the phosphorylation of 5'-OH-terminated sDNA in the double-stranded DNA probe when ATP is present, and λ-exonuclease can catalyze the degradation of the phosphorylated sDNA into small fragments. Then the cDNA forms a hairpin structure so that CdS QDs and AuNPs are in close contact, which can induce exciton-plasma interactions between CdS QDs and AuNPs. The exciton-plasma interactions significantly boost the photocurrent, enabling the "signal on" PEC determination of T4 PNK in the range of 10 - 1 U mL with a detection limit of 6 × 10 U mL. The PEC biosensor can also be used to screen enzyme inhibitors.
我们在此报告了 Au 纳米颗粒（AuNPs）/SnS/ZnInS 作为一种高性能的活性材料，用于通过酶反应诱导的 DNA 结构开关策略，灵敏地光电化学（PEC）测定 T4 多核苷酸激酶（T4 PNK）。为了构建 PEC 生物传感器，将由 CdS 量子点（QDs）标记的单链 DNA（sDNA）及其互补 DNA（cDNA）组成的双链 DNA 探针固定在 AuNPs/SnS/ZnInS 光活性材料上。当存在 ATP 时，T4 PNK 可以催化双链 DNA 探针中 5'-OH 末端 sDNA 的磷酸化，λ-核酸外切酶可以催化磷酸化的 sDNA 降解成小片段。然后 cDNA 形成发夹结构，使 CdS QDs 和 AuNPs 紧密接触，这可以诱导 CdS QDs 和 AuNPs 之间的激子-等离子体相互作用。激子-等离子体相互作用显著增强了光电流，使得 T4 PNK 的“信号开启”PEC 测定范围在 10-1 U mL 之间，检测限为 6×10 U mL。PEC 生物传感器还可用于筛选酶抑制剂。
