Photoelectrochemical Assay Based on SnO₂/BiOBr p–n Heterojunction for Ultrasensitive DNA Detection

Abstract

Herein, a photoelectrochemical (PEC) assay was designed for a highly sensitive DNA determination relying upon the SnO 2 /BiOBr p−n heterojunction as a photoactive material and SiO 2 as a signal quencher. Compared with most traditional heterojunctions, the SnO 2 /BiOBr p−n heterostructure not only lessened the recombination of the photogenerated electron−hole pairs but also promoted the light-harvesting in the ultraviolet−visible (UV−vis) region, leading to further enhanced photoelectric conversion efficiency and photocurrent, which demonstrated 12.1-fold and 6.4-fold increments versus those of pure SnO 2 and BiOBr, respectively. Additionally, the limited quantity of target DNA (a fragment of p53 gene) could be transformed into abundant output DNA−SiO 2 by employing the Nt•BstNBI enzyme-assisted signal amplification procedure, leading to a highly improved detection sensitivity of the biosensor. Then, output DNA−SiO 2 hybridized with the capture DNA anchored on the modified electrode surface, remarkably diminishing the PEC signal and thus achieving sensitive DNA determination. The elaborated PEC biosensor demonstrated outstanding performance within the linear range between 0.5 fM and 5 nM and a low limit of detection down to 0.18 fM, paving a new way for fabricating heterojunction with exceptional photoactive performance and demonstrating the enormous potential for detecting multitudinous biomarkers in bioanalysis and clinical therapy.

Recent developments in bismuth oxyhalide-based functional nanomaterials for biomedical applications

“…BiOX nanomaterials can be roughly divided into four categories based on the effect of different modifications, including the addition of nanocarbon materials to promote electron–hole separation, 93,95–99 polymers to benefit biocompatibility, 40,51,100–106 biomolecules to improve targeting, 107,108 and photosensitizers to enhance light absorption. 109–114…”

“…BiOX nanomaterials can be roughly divided into four categories based on the effect of different modifications, including the addition of nanocarbon materials to promote electron-hole separation, 93,[95][96][97][98][99] polymers to benefit biocompatibility, 40,51,[100][101][102][103][104][105][106] biomolecules to improve targeting, 107,108 and photosensitizers to enhance light absorption. [109][110][111][112][113][114] 2.3.1 The modification of BiOX with carbon-based materials. Modified carbon nanomaterials on the surface of BiOX to form composites not only have low cost and high chemical stability but also the synergistic effect between the two materials can substantially stimulate the catalytic activity of semiconductors.…”

“…In comparison to arginine and glycine, cysteine provides a unique environment for the formation of BiOBr nanosheets, in which Bi 3+ preferentially coordinate with thiol rather than carboxyl groups. BiOBr nanosheets form in small sizes and orient in the [110] direction, which was more favorable for rapid charge transfer. 40 2.3.4 The modification of BiOX with photosensitizers.…”

A photoelectrochemical immunosensor based on magnetic all-solid-state Z-scheme heterojunction for SARS-CoV-2 nucleocapsid protein detection

“…On the one hand, the process of immune sensing based on traditional semiconductor materials is complicated, and the immune process of electrode surface is interfered by the inherent absorption of solid-liquid interface [13] . On the other hand, most traditional single-phase semiconductors only display unsatisfactory initial photocurrent signals due to their low photoelectric conversion efficiency [14] . Therefore, it is urgent to design and synthesize a new photoelectric material that can simplify experimental steps and provide prominent PEC response.…”

Photocatalytic Conversion of Fructose to Lactic Acid by BiOBr/Zn@SnO2 Material

“…The coupling of SnO 2 with Bi-containing semiconductor materials has been studied as a new trend for composites that can improve photocatalytic performance [21]. Due to the traditional preparation methods, which are time-consuming, energy-intensive and have low purity [22], some other methods were referenced in this study, such as modified SnO 2 with BiOBr in one pot [23,24]. In this research, BiOBr and SnO 2 were chosen as original semiconductor materials.…”