Photoelectrochemical Biosensor for 5‐Formylcytosine Based on WS2/Bi/Bi2O2CO3 Nanocomposite and Rolling Circle Amplification. Issue 2 (9th December 2021)

• Record Type: Journal Article
• Authors: Wang, Qian; Yin, Huanshun; Zhou, Yunlei; Cao, Lulu; Yu, Zhengkun; Xu, Yamin; Ai, Shiyun
• Is Part Of: Chinese journal of chemistry. Volume 40:Issue 2(2022)
• Page Start: 247
• Page End: 255
• Publication Date: 2021-12-09
• Subjects: Semiconductors -- Photoelectrochemistry -- Biosensor -- Epigenetic modification -- Toxicology; Chemistry -- Periodicals; 540.5
• DOI: 10.1002/cjoc.202100667
• Languages: English
• ISSNs: 1001-604X

Abstract

Comprehensive Summary: As a key epigenetic modification, 5‐formylcytosine (5fC) controls many important cell functions, such as gene expression and cell differentiation. However, 5fC exists in mammalian tissues and cells with low content, and its structure is highly similar to 5‐methylcytosine (5mC), 5‐hydroxymethylcytosine (5hmC) and 5‐carboxycytosine (5caC), which requires the detection method for detecting 5fC with high sensitivity and specificity. In this experiment, WS2 /Bi/Bi2 O2 CO3 was used as the photoactive material, 5fC antibody was used as the target molecule recognition reagent, and rolling amplification (RCA) was employed as the signal amplification strategy to construct a novel photoelectrochemical biosensor for detecting 5‐formylcytosine deoxynucleotide (5fdCTP). Firstly, WS2 /Bi/Bi2 O2 CO3 nanocomposite was prepared and characterized, and then modified on the ITO electrode. Then, polyacrylic acid (PAA) was immobilized by electrostatic adsorption, which was employed as the antibody capture reagent based on the covalent reaction of –COOH on PAA with –NH2 on Ab. Subsequently, 5fdCTP was recognized through immunoreaction, triggering the subsequent rolling circle amplification reaction with the aid of the crosslinker of Zr 4+ . Finally, positive methylene blue (MB) was adsorbed by negative ssDNA, resulting in an increased photoelectric conversion efficiency of WS2 /Bi/Bi2 O2 CO3 and improved detection sensitivity. The linear range of the PEC biosensor for detecting 5fdCTP was 0.05—100 nmol/L, and the minimum detection concentration was 12.4 pmol/L (S/N = 3). The applicability of this method has been evaluated by studying the influence of Cd 2+ and antibiotic concentration on the 5fC content in the genomic DNA of maize seedlings. Abstract : A novel photoelectrochemcial immunosensor was constructed for 5‐formylcytosine deoxynucleotide (5fdCTP) detection using WS2 /Bi/Bi2 O2 CO3 as the photoactive material. After combined with Bi/Bi2 O2 CO3, the photoactivity of WS2 was improved greatly due to the formation of Heterojunction and Bi doping, which facilitated the electron migration, inhibited the recombination of photogenerated electron‐hole pair. The specific recognition of 5fdCTP was achieved based on anti‐5fC antibody through the immunoreaction. Then, owing to the specific covalent reaction between Zr 4+ and phosphate group, ssDNA labeled with phosphate at its 5'‐terminal end was captured on electrode surface, which triggered the further signal amplification of rolling circle amplification, following with the adsorption of positive methylene blue for improvement of the photocurrent.