Dual-Signaling Photoelectrochemical Biosensor Based on Biocatalysis-Induced Vulcanization of Bi₂MoO₆ Nanosheets

Abstract

A magnetic-assisted photoelectrochemical (PEC) and colorimetric (CL) dual-modal biosensing platform with high precision was established to monitor prostate-specific antigen (PSA) based on Bi2MoO6 nanosheets (BMO) by coupling the aptamer-guided hybridization chain reaction (HCR) with the hydrolysate-induced vulcanization reaction of Bi2MoO6 nanosheets. Upon addition of PSA, trigger DNA (tDNA) was released by the interaction between the target analyte and the aptamer and then further hybridized with anchor DNA (aDNA) conjugated on magnetic beads (MBs). The as-released tDNA initiated the target-assisted HCR in the presence of two alternating hairpin sequences (Bio-H1 and Bio-H2) to produce nicked long double-stranded DNA on the surface of MBs, where numerous alkaline phosphatase (ALP) enzymes could assemble with MBs through the biotin–avidin reaction, resulting in the hydrolysis of sodium thiophosphate (TP) to H2S. The as-produced H2S reacted with BMO to form vulcanized BMO (BMO-S), thus leading to obvious enhanced PEC performance under visible light with the color change from light yellow to brown. Having optimized the test conditions, the magnetic-assisted biosensing system holds a good quantitative diagnosis sensitivity area in a range of 5.0 pg mL–1–100 ng mL–1 with a calculated detection limit down to 3.5 pg mL–1. Meanwhile, a visual colorimetric assay on basis of the change in the color of the materials was also realized. Given the exceptional performance of the constructed biosensor, it may possess great promise as an advanced bioanalytical tool for practical applications.

Recent advances on the electrochemical and optical biosensing strategies for monitoring microRNA-21: a review

“…A very recent study took advantage of magnetic beads and an electrochemical biosensor-type aptamer was created along with Bi 2 MoO 6 nanosheets for cancer biomarker detection. 75…”

“…A very recent study took advantage of magnetic beads and an electrochemical biosensortype aptamer was created along with Bi 2 MoO 6 nanosheets for cancer biomarker detection. 75 Electrochemistry-based tools have been widely utilized in recent years for ensuring high-quality human life through their selective sensitivity and rapid detection of different markers. 76 In conclusion, the electrochemical biosensors have been successfully employed for the precise and sensitive detection of the miR-21 biomarker in the patient serum samples.…”

Flexible and High-Throughput Photothermal Biosensors for Rapid Screening of Acute Myocardial Infarction Using Thermochromic Paper-Based Image Analysis

“…To confirm the accuracy of the tests, the test results of the relevant ELISA kits are expressed in Table S1 and Figure C, and the correlation between the two testing methods was counted and analyzed by the t -value test method. The results showed that the t-values of all tested samples were less than 2.78 ( t crit [0.05,4] = 2.78), − which suggested that the colorimetric method using thermochromic paper was not significantly different from the test results of the commercial ELISA kits. It was noted that the grayscale obtained from the assessment of cTnI target values in serum with thermochromic paper was smaller than the test results of the ELISA kit, which might be explained by the interference of the test environment and the restricted use of color extraction on the smartphone.…”

Regenerative Strategy of Gold Electrodes for Long-Term Reuse of Electrochemical Biosensors

“…After washing, the first EC cleaning was performed by dipping in 10 mM H 2 SO 4 electrolyte, and CV was performed with a scan rate of 100 mV/s in 0 to −1.8 V. Afterward, the electrode was washed by PBS 3 times, and the second EC cleaning was performed. CV was performed with a scan rate of 200 mV/s in −1.2 to 1.2 V in 5 mM K 3 Fe(CN) 6 . Then, the electrode was washed with PBS 3 times, and the signal was measured in 5 mM K 3 Fe(CN) 6 as an electrolyte.…”