Construction of Photoelectrochemical DNA Biosensors Based on TiO2@Carbon Dots@Black Phosphorous Quantum Dots

Abstract

In this work, carbon dots (CDs) and black phosphorus quantum dots (BPQDs) were used to decorate titanium dioxide to enhance the photoelectrochemical (PEC) properties of the nanocomposites (TiO2@CDs@BPQDs), and the modified nanocomposites were used to sensitively detect DNA. We used the hydrothermal method and citric acid as a raw material to prepare CDs with good dispersion and strong fluorescence properties. BPQDs with a uniform particle size were prepared from black phosphorus crystals. The nanocomposites were characterized by fluorescence spectroscopy, UV-Vis absorption spectroscopy, Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). The preparation method of the working electrode was explored, the detection conditions were optimized, and the sensitive detection of target DNA was achieved. The results demonstrate that CDs and BPQDs with good optical properties were successfully prepared, and they were successfully combined with TiO2 to improve the PEC performance of TiO2@CDs@BPQDs. The TiO2-based PEC DNA detection method was constructed with a detection limit of 8.39 nM. The constructed detection method has many advantages, including good sensitivity, a wide detection range, and good specificity. This work provides a promising PEC strategy for the detection of other biomolecules.

Development of Two-Dimensional Functional Nanomaterials for Biosensor Applications: Opportunities, Challenges, and Future Prospects

“…This biosensor provided a label-free detection of small biomolecules. The BP nanoparticles were used as fluorescent biosensing for the detection of DNA [179,180]. BP nanoparticles were synthesized from red phosphorus using high-pressure phase transformation.…”

Sustainable approaches towards green synthesis of TiO2 nanomaterials and their applications in photocatalysis‐mediated sensing to monitor environmental pollution

“…Similarly, Song and colleagues illustrated the assembly of photoelectrochemical DNA‐based biosensors prepared using carbon dots (CDs), TiO 2 , and black phosphorus quantum dots (BPQDs). [ 95 ] The obtained results demonstrated that BPQDs and CDs possessed unique optical properties when combined with TiO 2 to develop a TiO 2 @CDs@BPQDs hybrid nanostructure, and exhibited much better PEC‐enabled biosensing properties towards DNA detection. [ 95 ] Consequently, the low detection limit of 8.39 nM along with a wide detection range, improved the sensitivity, and specificity that could be recorded.…”

“…[ 95 ] The obtained results demonstrated that BPQDs and CDs possessed unique optical properties when combined with TiO 2 to develop a TiO 2 @CDs@BPQDs hybrid nanostructure, and exhibited much better PEC‐enabled biosensing properties towards DNA detection. [ 95 ] Consequently, the low detection limit of 8.39 nM along with a wide detection range, improved the sensitivity, and specificity that could be recorded. In one study, the preparation of a PEC sensor using TiO 2 P25 NPs has been reported by Mokhtar and co‐workers.…”

A Review on Carbon Quantum Dot Based Semiconductor Photocatalysts for the Abatement of Refractory Pollutants

“…CQDs and other quantum dots, such as silicon, phosphorous, germanium, or from compound semiconductor materials, such as CdSe, CdTe, and PbS have been discovered and exhibits strong PLQY, and tuneable photoluminescence in general. However, the high cost, toxic nature, complex method of preparation and use of hazardous precursors in the synthetic procedure limit their mass production and use in practical applications [49,50] …”

“…However, the high cost, toxic nature, complex method of preparation and use of hazardous precursors in the synthetic procedure limit their mass production and use in practical applications. [49,50] For the synthesis of CQDs, two alternative approaches, "topdown" and "bottom-up," have generally been used, depending on the type of source or precursor materials. [23] The "top-down" synthetic process involves employing laser ablation, arc discharge, ultrasonic treatment, and electrochemical techniques to break down bigger carbon structures such as graphite, carbon nanotubes (CNTs), and nano diamonds into CQDs.…”