The photoluminescence (PL) quantum yield of single-walled carbon nanotubes (SWNTs) is relatively low, with various quenching effects by metallic species reported in the literature. Here, we report the first case of metal enhanced fluorescence (MEF) of surfactant-coated carbon nanotubes on nanostructured gold substrates. The photoluminescence quantum yield of SWNTs is observed to be enhanced more than 10-fold. The dependence of fluorescence enhancement on metal-nanotube distance and on surface plasmon resonance (SPR) of the gold substrate for various SWNT chiralities is measured to reveal the mechanism of enhancement. Surfactant-coated SWNTs in direct contact with metal exhibit strong MEF without quenching, suggesting a small quenching distance for SWNTs on the order of the van der Waals distance, beyond which the intrinsically fast non-radiative decay rate in nanotubes is little enhanced by metal. The metal enhanced fluorescence of SWNTs is attributed to radiative lifetime shortening through resonance coupling of SWNT emission to the re-radiating dipolar plasmonic modes in the metal.

Metal-Enhanced Fluorescence of Carbon Nanotubes

The advent of miniaturized, fiber-based, Raman spectrometers provides a clear path for the wide implementation of surface-enhanced Raman scattering (SERS) in analytical chemistry For instance, min

Detection of Buried Explosives Using a Surface-Enhanced Raman Scattering (SERS) Substrate Tailored for Miniaturized Spectrometers.

Cyclized conjugated microporous polymer-coated silica nanospheres as fluorescent sensors for iron (III) and chromium (III)

Highly selective fluorescence probe for imidacloprid measurement based on fluorescence resonance energy transfer

Solvent exchange is a simple method to produce surface nanodroplets on a substrate for a wide range of applications by displacing a solution of good solvent, poor solvent, and oil (solution A) by a...

Viscosity-Mediated Growth and Coalescence of Surface Nanodroplets

The microwell plate/microtiter plate is among the most widely used tools in immune assays. In this paper, we report on a sensitive method for enhancing fluorescence emission detection by simply adding several droplets of an immiscible organic compound into the microwells before detection. To prove the concept, human IgA was determined on a microwell plate using this droplet enhanced fluorescence (DEF) detection method. An obvious enhancement in fluorescence was observed. The detection limit (LOD) was about 1/20 times and the sensitivity was 4 times greater than that without droplets. To prove the use of the method for disease diagnosis, the IgG of measles in human plasma was determined using the proposed DEF method. A LOD of around 1/5 times and a sensitivity of 4 times the DEF were easily achieved compared to ELISA with a conventional fluorescence detection.

Droplet Sensitized Fluorescence Detection for Enzyme-Linked Immune Sorbent Assays on Microwell Plate

Microsphere amplified fluorescence and its application in sensing.

To improve the sensitivity of fluorescence detection to microwell plate to match the up-to-date bio-analysis, a simple and easy-to-access approach to efficiently sensitize the fluorescence detection to microwell plate was constructed. Taking the advantage of higher refractive index of soda lime glass than that of ambitious aqueous solution, several transparent soda lime glass microspheres were introduced into the wells on microwell plate to enhance the fluorescence detection before the generation of fluorophores. Around 2500 times enhancement of sensitivity for model resorufin was obtained through the microsphere enhanced fluorescence (MSEF), meanwhile, around 500 times lowered limitation of detection (LOD) was achieved in the detection of resorufin through the proposed MSEF. To proof the performance of MSEF in bio-measurement, the human IgA assay was implemented on the microwell plate coupled with MSEF. Around 70 times of lowered LOD could be obtained by utilizing the common microwell plate reader. To confirm the practicality of MSEF in the disease diagnosis, the measurements of human measles Ig G and human cancer marker carcinoembryonic antigen (CEA) were respectively performed by the microwell plate coupled MSEF. The sensitivities for human measles Ig G and for human cancer marker CEA were both greatly improved and those of LOD were lowered through the detections conducted by the fluorescence microscope or by the microwell plate reader. We expect the proposed MSEF could be a handy approach to improve the performance of microwell plate to widely benefit the operators of microwell plate.

A simple and efficient approach to sensitize the fluorescence detection to microwell plate

Corrigendum to “A simple and efficient approach to sensitize the fluorescence detection to microwell plate” [Sens. Actuators B Chem. 343 (2021) 130070]

Tsuguhiro Kaneko

Papers

Droplet Sensitized Fluorescence Detection for Enzyme-Linked Immune Sorbent Assays on Microwell Plate

Microsphere amplified fluorescence and its application in sensing.

A simple and efficient approach to sensitize the fluorescence detection to microwell plate

Corrigendum to “A simple and efficient approach to sensitize the fluorescence detection to microwell plate” [Sens. Actuators B Chem. 343 (2021) 130070]