Nanosheets-assembled hollow CdIn2S4 microspheres-based photoelectrochemical and fluorescent dual-mode aptasensor for highly sensitive assay of 17 beta-estradiol based on magnetic separation and enzyme catalytic amplification

Key Words:IMMUNOASSAY

Abstract:The specific and accurate quantitation of environmental endogenous estrogens is traditionally recognized as a vital strategy in environment, health and disease. In this work, nanosheet-assembled hollow CdIn2S4 microspheres were prepared by a one-pot solvothermal method, which attained strong photoelectrochemical signals and applied to build a novel dual-mode aptasensor by integration with fluorescent signals for accurate and selective detection of 17 beta-estradiol (E2). Specifically, alkaline phosphatase (ALP) modified E2 aptamer (ALP-Apt) was released from magnetic beads (which can effectively achieve the hydrolysis of L-ascorbic acid 2-phosphate (AAP) to form ascorbic acid (AA)), in turn increasing the photocurrents at the photoelectric nano-interface. Simultaneously, the decrease in the double stranded DNA (dsDNA) on the magnetic beads surface also weakened fluorescence signals upon the presence of Helixyte Green (TM). Under optimal conditions, the as-developed dual-mode aptasensor displayed the wide linear range of 0.1 similar to 200 nM by the PEC analysis and 0.1 similar to 100 nM by the fluorimetric assay for detecting E2. This method provides a novel and efficient dual-mode biosensing strategy for promising analysis of small molecular in environmental pollutants.

Volume:347

Issue:

Translation or Not:no