Plasmon-modulated fluorescence nanoprobes for enzyme-free DNA detection via target signal enhancement and off-target quenching

Dual-Mode Detection of Cysteamine Using Ag Nanoparticle-Riboflavin Composites

“…As known, the small NPs with a diameter of <30 nm can serve as excellent fluorescence quenchers because absorption is dominant, while relatively larger particles, typically >30 nm in diameter, tend to scatter, making them more suitable as a fluorescence enhancer. , On the other hand, the spectra overlap between the LSPR band of plasmonic nanoparticles and the excitation/emission band of the emitter also has a greater influence on the fluorescence of emitters . Hence, in order to obtain the PEF and the quenching of RF, respectively, Ag@SiO 2 with big core size and small Ag NPs were chosen.…”

“…In summary, the modulation of the fluorescence signals through the PEF depends on many factors, including particle size, concentration, proximity to the fluorophore, and spectral overlap. Typically, particles smaller than 30 nm quench fluorescence due to absorption, while larger particles enhance fluorescence by scattering light . Under optimal conditions, such as appropriate spectral overlaps and distances, PEF occurs due to increased excitation rates and radiative transition rates.…”

“…Under optimal conditions, such as appropriate spectral overlaps and distances, PEF occurs due to increased excitation rates and radiative transition rates. Conversely, when the distance is less than 10 nm, metal nanostructures efficiently quench fluorescence signals through nonradiative energy transfer. , Moreover, the relative concentrations of dye molecules and metal nanoparticles influence the average distance, affecting the fluorescence enhancement or quenching effects. In this study, Ag@SiO 2 NPs acted as fluorescence enhancers, while smaller Ag NPs served as fluorescence quenchers.…”

“…Typically, particles smaller than 30 nm quench fluorescence due to absorption, while larger particles enhance fluorescence by scattering light. 26 Under optimal conditions, such as appropriate spectral overlaps 28 and distances, PEF occurs due to increased excitation rates and radiative transition rates. Conversely, when the distance is less than 10 nm, metal nanostructures efficiently quench fluorescence signals through nonradiative energy transfer.…”

PCR-Free, Label-Free, and Centrifugation-Free Diagnosis of Multiplex Antibiotic Resistance Genes by Combining mDNA-Au@Fe3O4 from Heating Dry and DNA Concatamers with G-Triplex

“…Consequently, the need for a simple, rapid, and high-throughput approach to detect and monitor the dissemination of ARGs within bacterial populations has become increasingly pressing. PCR-free methods for detecting ARGs have also been developed, such as electrochemical/photoelectrochemical, , fluorescence sensors, paper-based chips, and colorimetric methods . Among these methods, fluorescence sensors are widely used for genetic testing due to their high sensitivity and ease of operation.…”