Colorimetric chiral discrimination of lysine enantiomers and configurable logic gate operation based on fluorescein-functionalized polydiacetylene vesicles

This study describes a sensitive sensor for based on fluorescein-functionalized diacetylene (F-DA) chromatic conjugated vesicle which allows colorimetric visualization for the chiral recognition of lysine by the naked-eye.

A LAMP Protocol for the Detection of ‘Candidatus Phytoplasma pyri’, the Causal Agent of Pear Decline

Phytoplasmas are cell-wall-less bacteria that cause diseases in approximately 1,000 plant species. ‘Candidatus Phytoplasma pyri’, the causal agent of pear decline, induces various symptoms on its hosts, leading to weakening and dieback of the plants, reduced fruit size and yield, and, consequently, considerable financial losses in all pear-growing areas. Fighting this disease requires a reliable and inexpensive method for pathogen detection in propagation material as well as plant stocks in orchards and breeding facilities. Here, we present a field-suitable detection protocol for ‘Ca. P. pyri’ based on loop-mediated isothermal amplification (LAMP) targeting the phytoplasmal 16S ribosomal DNA sequence. The combination of a simplified sample preparation method based on sodium hydroxide and colorimetric visualization of LAMP results enables a laboratory-independent pathogen detection. The detection limit is comparable with analysis by polymerase chain reaction; however, the pear decline LAMP detection method is superior in terms of ease of use, cost, and time effectiveness for obtaining results.

A simple, fast, and sensitive colorimetric assay for visual detection of berberine in human plasma by NaHSO4-optimized gold nanoparticles

Herein, we report a simple, fast and sensitive colorimetric visualization of berberine in human plasma using NaHSO4-optimized gold nanoparticles. The LOD in human plasma is 0.24 μg mL−1by the naked eye and 0.06 μg mL−1by UV-vis spectroscopy.

Etching of unmodified Au@Ag nanorods: a tunable colorimetric visualization for the rapid and high selective detection of Hg2+

A simple and cost-effective colorimetric approach based on unmodified Au@Ag nanorods (Au@Ag NRs) was developed for Hg2+ detection.