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

Microfluidic paper-based analysis device applying black phosphorus nanosheets@MWCNTs-COOH: A portable and efficient strategy for detection of β-Lactoglobulin in dairy products

This study prepared a novel, portable and cost-effective microfluidic paper-based electrochemical analysis device (μ-PAD) using black phosphorus nanosheets@carboxylated multi-walled carbon nanotubes (BPNSs@MWCNTs-COOH) nanocomposites for β-lactoglobulin (β-LG) detection. At the appreciate ratio, the synthesized BPNSs@MWCNTs-COOH was demonstrated to not only serve as a high-quality substrate for the specific aptamer immobilization, but also improve the electron transfer capability of the sensing interface. The μ-PADs, utilizing BPNSs@MWCNTs-COOH and aptamer recognition, exhibited a wider detection range (10-1000 ng mL-1) and lower detection limit (LOD: 0.12 ng mL-1) for β-LG, and demonstrated enhanced specificity, satisfactory anti-interference ability and stability. When applied to the β-LG determination in dairy samples, the μ-PAD yielded β-LG concentrations highly correlated with those obtained using the HPLC method (R2: 0.9982). These results emphasized the reliable performance of the developed μ-PADs in β-LG allergen quantification, highlighting their potential as an efficient platform for the rapid screening of β-LG allergens.

TiO2-guanine as a new amalgamation compound for fabrication of a disposable biosensor with high sensitivity and rapid detection of H1N1 swine flu virus

A TiO2-guanine nanocomposite (TG NC)-based electrochemical biosensor was immobilized with hemagglutinin (HA) gene specific probe with 5' NH2 group on screen-printed gold electrode (probe(ss)DNA-TG-SPGE). The modified biosensor was examined for H1N1 swine flu virus. TG NCs along with precursors were characterized spectroscopically and morphologically by employing several approaches. Electrochemical investigations were performed with the help of cyclic voltammetric (CV) and electrochemical impedance spectroscopy (EIS) in 0.1 M phosphate buffer saline (PBS; pH 7.4) with 1 µM methylene blue (MB) redox indicator. For better detection of single-stranded virus DNA, the modified electrode was optimized at various concentrations, pH, and scan rates. The modified biosensor showed high sensitivity (40.32 μA/ng.cm2), low LOD (0.00024 ng/6 µL), and broad linear range 0.0002-20 ng/6µL with coefficient of determination of R2=0.9981 for H1N1 virus detection. The HA gene-modified biosensor presented decent stability and specificity against different infectious pathogens including H3N2 virus and human DNA with negative response. Furthermore, the modified biosensor also responded well for real sample target DNA detection with a recovery of >96%. The simply designed HA gene-modified biosensor transduces decreased current response towards target-specific (ss)DNA binding and could be used as a rapid detection tool for H1N1 swine flu virus diagnosis.

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

New possibilities for the development of biosensors that are ready to be implemented in the field have emerged thanks to the recent progress of functional nanomaterials and the careful engineering of nanostructures. Two-dimensional (2D) nanomaterials have exceptional physical, chemical, highly anisotropic, chemically active, and mechanical capabilities due to their ultra-thin structures. The diversity of the high surface area, layered topologies, and porosity found in 2D nanomaterials makes them amenable to being engineered with surface characteristics that make it possible for targeted identification. By integrating the distinctive features of several varieties of nanostructures and employing them as scaffolds for bimolecular assemblies, biosensing platforms with improved reliability, selectivity, and sensitivity for the identification of a plethora of analytes can be developed. In this review, we compile a number of approaches to using 2D nanomaterials for biomolecule detection. Subsequently, we summarize the advantages and disadvantages of using 2D nanomaterials in biosensing. Finally, both the opportunities and the challenges that exist within this potentially fruitful subject are discussed. This review will assist readers in understanding the synthesis of 2D nanomaterials, their alteration by enzymes and composite materials, and the implementation of 2D material-based biosensors for efficient bioanalysis and disease diagnosis.

Sustainable approaches towards green synthesis of TiO2 nanomaterials and their applications in photo-catalysis mediated sensingtomonitor environmental pollutions

Nanomaterials are gaining enormous interests owing to their novel applications that have been explored nearly in every field of our contemporary society. In this scenario, preparations of nanomaterials following green routes have attracted widespread attention in terms of sustainable, reliable and environmentally friendly practice to produce diverse nanostructures. In this review, we summarized the fundamental processes and mechanisms of green synthesis approaches of TiO₂ NPs. We explore the role of plants and microbes as natural bioresources to prepare TiO₂ NPs. Particularly, focused have been made to explore the potential of TiO₂ based nanomaterials to design variety of sensing platforms by exploiting the photo-catalysis efficiency under the influence of light source. Such types of sensing can of massive importance to monitor the environmental pollutions and thereby to invent advanced strategies to remediate hazardous pollutants to offer clean environment.

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

Photocatalysis is a green approach frequently utilised to eliminate a variety of environmentally hazardous refractory pollutants. Accordingly, the modification of semiconductor photocatalysts with Carbon Quantum Dots (CQDs) is of great importance for the treatment of such pollutants due to their attractive physical and chemical properties. CQDs are a perfect candidate to handle photocatalysts of high-performance since they operate as co-catalysts and as visible light harvesters. The higher separation rate of electron-hole pairs in the photocatalytic system is attributable to better photodegradation efficiency. This review classifies CQD based photocatalysts as pure, doped and composite materials and discusses the specific advantages of CQDs in visible light-driven photocatalysis. In this work, the versatile roles of CQDs in CQD-based photocatalytic systems are thoroughly discussed and s u mmarised.