Highly Sensitive Photoelectrochemical Biosensor Based on Quantum Dots Sensitizing Bi₂Te₃ Nanosheets and DNA-Amplifying Strategies

Abstract

In this work, Bi2Te3 nanosheets treated with N-vinyl-pyrrolidinone showed highly sufficient and stable photocurrent for being used as a novel photoactive material. Accordingly, with CdTe quantum dots (QDs) sensitizing Bi2Te3 nanosheets, photoelectrochemical (PEC) biosensor coupling of DNA-amplifying strategies was constructed for sensitive miRNA-21 detection. Initially, the Bi2Te3 nanosheets on the electrode have conductive surface states with dissipationless electronic property, thus providing a highly stable photocurrent and a large surface-to-volume ratio. Then, with the participation of target miRNA-21 and auxiliary DNA, strand displacement amplification took place, thereby opening substantial DNA hairpins for triggering the next hybridization chain reaction (HCR). Through the HCR, long DNA tails decorated with CdTe QDs could thus be assembled on the electrode for enhancing the photocurrent of Bi2Te3 nanosheets. As a result, the proposed PEC biosensor showed a wide detection range from 10 fM to 100 pM with a detection limit of 3.3 fM, displaying a promising avenue to construct simple, ultrasensitive, and stable analytical techniques and tremendous potential in bioanalysis and early clinical diagnosis.

Ultrasensitive Surface‐Enhanced Raman Scattering (SERS) Detection For miRNA‐182 Based on CdS/MoS2@AuNPs Fabricated by Atomic Layer Deposition (ALD)

“…Comparing with previous work, the CdS/MoS 2 @AuNPs based SERS platform prepared in this paper has a better linear range and the lowest detection limit (Figure 5d). [ 42–50 ]…”

“…Comparing with previous work, the CdS/MoS 2 @ AuNPs based SERS platform prepared in this paper has a better linear range and the lowest detection limit (Figure 5d). [42][43][44][45][46][47][48][49][50] Furthermore, 20 points were randomly selected from the CdS/MoS 2 @AuNPs' substrate, and the relative standard deviation (RSD) value after the internal standard calibration strategy was 2.54%, indicating that the substrate has good uniformity (Figure S18, Supporting Information). Meanwhile, the platform also showed good performance when applied to samples involving human serum, and typical SERS spectra acquired from the miRNA-182 spiked human serum are shown in Figure S19 (Supporting Information).…”

Band alignment of type-I SnS2/Bi2Se3 and type-II SnS2/Bi2Te3 van der Waals heterostructures for highly enhanced photoelectric responses

“…For example, Bi 2 Se 3 and Bi 2 Te 3 show narrow band gaps (0.3-1.0 eV) [18,19], conductive surface states, and high specific surface areas. Furthermore, Bi 2 Se 3 and Bi 2 Te 3 are typical topologically insulator-layered materials [20,21] with an outer spinmomentum-locked Dirac cone and an internal insulating band gap [22]. These topologically protected and massless Dirac-type surface states are considered superior electrodes [23,24].…”

A photo-electrochemical aptasensor for the determination of severe acute respiratory syndrome coronavirus 2 receptor-binding domain by using graphitic carbon nitride-cadmium sulfide quantum dots nanocomposite

“…To fabricate a photo-electrochemical biosensor, photoactive materials such as quantum dots (QD) [ [23] , [24] , [25] , [26] ], titanium dioxide (TiO 2 ) [ 25 , 27 ], and graphitic carbon nitride (gC 3 N 4 ) [ 27 , 28 ] have been used to convert photons to electrons and then generate the photo-current.…”