Light-activated oxidative capacity of isoquinoline alkaloids for universal, homogeneous, reliable, colorimetric assays with DNA aptamers.

Aptamers are good affinity receptors for bio-assays, while colorimetric method is suitable for point-of-care sensing via direct visualization. But previously aptamers often need complex re-engineering for colorimetric measurement at the cost of affinity and performance. Here isoquinoline alkaloids are found to own unique light-activated oxidative capacity, which can be specifically triggered by unmodified aptamers.

Light-activated, dual-mode fluorescence and colorimetric detection of estradiol with high fidelity based on aptamer's special recognition.

The intake of estradiol residue from food will lead to health problems, so the rapid and reliable detection of estradiol residue is essential. Multi-mode assays are inherently self-correcting and self-validating, providing more reliable, interference-resistant, high-fidelity results. Here, we developed a dual-mode method to achieve a rapid, reliable, and sensitive detection of estradiol.

Versatile DNA Balances via Adjacent Base Stacking for Homogeneous Assay of Energy Parameters, Small Molecules, And Ribonuclease.

Homogeneous assays often obviate any separation and washing steps, thus minimizing the risks of contamination and false positive. DNA toehold exchange is a homogeneous, reversible process whose thermodynamic properties can be finely tuned for various assay applications. However, the developed probes often rely on direct interactions of analytes with DNA strands involved in toehold exchange, limiting the versatility of probe design.

Simulation-Guided Rational Design of DNA Probe for Accurate Discrimination of Single-Nucleotide Variants Based on "Hill-Type" Cooperativity.

The accurate discrimination of single-nucleotide variants is of great interest for disease diagnosis and clinical treatments. In this work, a unique DNA probe with "Hill-type" cooperativity was first developed based on toehold-mediated strand displacement processes. Under simulation, this probe owns great thermodynamics advantage for specificity due to two mismatch bubbles formed in the presence of single-nucleotide variants.

Target-triggered double fluorescent biosensors for rapid and sensitive detection of long-chain perfluorinated compounds using DNA probe and lysozyme fiber.

Perfluorinated compounds (PFCs) are useful man-made chemicals and serve as new emerging organic pollutants due to their environmental and health concerns. Chromatography-mass detection methods often need complex procedure and are also too expensive, so there is a critical demand to develop rapid, inexpensive, easy-to-operate and sensitive methods for PFCs detection. In this work, double fluorescent biosensors ('DT sensor' and 'FT sensor') have been designed to quantitatively detect long-chain perfluorinated compounds (PFCs), due to their strong hydrophobic interaction with DNA probe or lysozyme fiber.

Ovalbumin-coated gold nanoparticles with interesting colloidal stability for colorimetric detection of carbaryl in complex media.

Pesticide carbaryl can cause serious environmental pollution and its sensitive detection is of increasing interest. Gold nanoparticles (AuNPs) are classically colorimetric probes for detection of many analytes, but the instability in complex media limits their application. Here, Au@Ova NPs have been developed as a stable, effective, sensitive, and selective sensing system for colorimetric detection of carbaryl.

A green photocatalytic-biosensor for colorimetric detection of pesticide (carbaryl) based on inhibition of acetylcholinesterase.

Carbaryl is a widely-used carbamate pesticide and the detection of its residues in environmental, food and clinical samples is of great importance. In this sturdy, we developed a green photocatalytic-biosensor based on double strand DNA-SYBR green I complex for sensitively colorimetric detection of carbaryl. This green photocatalytic-biosensor can oxidize 3,3',5,5'-tetramethylbenzidine (TMB) into blue ox-TMB.