Investigating the effect of 6-mercaptohexanol on the performance of a biosensor based on nanosurface energy transfer between gold nanoparticles and quantum dots

Highly sensitive fluorescent probe and portable test strip based on polyacrylic acid functionalized quantum dots for rapid visual detection of malachite green

Malachite green (MG) has been banned in aquaculture by many countries due to its high carcinogenicity, high teratogenicity, and easy residue. However, it is cheap and efficient characteristics have made it difficult to eliminate in recent decades, so it is essential to develop a rapid and accurate detection method for MG. Here, a highly Sensitive fluorescent probe based on polyacrylic acid (PAA) functionalized CdSe/CdxZn1-xS quantum dots (QDs) was prepared for the determination of MG. QDs functionalized by PAA (QDs@PAA) were used as energy donors, and MG was used as energy acceptor to construct fluorescence resonance energy transfer (FRET) system. The fluorescence of QDs@PAA could be linearly quenched by MG in the range of 0.05 ⁓ 2 μM, and the detection limit was 0.011 μM. In addition, a small amount of QDs@PAA (30 μL) was printed on the solid substrate by inkjet printing technology to prepare fluorescent test strips. When the concentration of MG was 2 μM, the fluorescent test strips were quenched and the detection process could be completed within 10 s, demonstrating significant potential for rapid visual detection of MG.

Surfactant stabilized gold nanomaterials for environmental sensing applications - A review

Surfactant stabilized Gold (Au) nanomaterials (NMs) have been documented extensively in recent years for numerous sensing applications in the academic literature. Despite the crucial role these surfactants play in the sensing applications, the comprehensive reviews that highlights the fundamentals associated with these assemblies and impact of these surfactants on the properties and sensing mechanisms are still quite scare. This review is an attempt in organizing the vast literature associated with this domain by providing critical insights into the fundamentals, preparation methodologies and sensing mechanisms of these surfactant stabilized Au NMs. For the simplification, the surfactants are divided into the typical and advanced surfactants and the Au NMs are classified into Au nanoparticles (NPs) and Au nanoclusters (NCs) depending upon the complexity in structure and size of the NMs respectively. The preparative methodologies are also elaborated for enhancing the understanding of the readers regarding such assemblies. The case studies regarding surfactant stabilized Au NMs were further divided into colorimetric sensors, surface plasmonic resonance (SPR) based sensors, luminescence-based sensors, and electrochemical/electrical sensors depending upon the property utilized by the sensor for the sensing of an analyte. Future perspectives are also discussed in detail for the researchers looking for further progress in that particular research domain.