Glucose Sensing in Human Whole Blood Based on Near-Infrared Phosphors and Outlier Treatment with the Programming Language "R"

Analytical detection of the bioactive molecules dopamine, thyroxine, hydrogen peroxide, and glucose using CsPbBr3 perovskite nanocrystals

Qualitative and quantitative detection of biologically important molecules such as dopamine, thyroxine, hydrogen peroxide, and glucose, using newer and cheaper technology is of paramount importance in biology and medicine. Anion exchange in lead halide perovskites, on account of its good emission yield, facilitates the sensing of these molecules by the naked eye using ultraviolet light. Simple chemistry is used to generate chloride ions from analyte molecules. Dopamine and thyroxine have an amine functional group, which forms an adduct with an equivalent amount of volatile hydrochloric acid to yield chloride ions in solution. The reducing nature of hydrogen peroxide and glucose is used to generate chloride ions through a reaction with sodium hypochlorite in stoichiometric amounts. The emission of CsPbBr3-coated paper/glass substrates shifts to the blue region in the presence of chloride ions. This helps in the detection of the above biologically important molecules up to parts per million (ppm) levels by employing fundamental chemistry aspects and well-known anion exchange in perovskite nanocrystals. The preparation of better and more efficient sensors, which are predominantly important in science and technology, can thus be achieved by developing the above novel, cost-effective alternative sensing method.

A convenient paper-based fluorescent aptasensor for high-throughput detection of Pb2+ in multiple real samples (water-soil-food)

Lead ion (Pb²⁺) is one of the most toxic and widely polluted heavy metal ions. Given the potential health risks and economic losses associated with Pb²⁺, the rapid detection of Pb²⁺ using fluorescent aptasensors is of significant importance in evaluating food safety. A rapid, facile and economic fluorescent aptasensor using convenient paper as the sensing substrate was designed to high-throughput detect Pb²⁺ in complex samples within about 45 min. The Pb²⁺ changed the conformation of FAM-modified Apt from a random coil to a stable G-quadruplex structure. And then Dabcyl-labeled cDNA was added to form double-stranded DNA with the Apt that did not form a G-quadruplex structure, resulting in a weak fluorescence due to the fluorescence resonance energy transfer (FRET). The fluorescent aptasensor showed a positive correlation with Pb²⁺ concentration, and a linear relationship was obtained in the range of 0.01-10 μM with LOD of 6.1 nM. In addition, this method has been successfully used for the determination of Pb²⁺ in water, soil and various foods containing complex substrates. Meanwhile, the high-throughput detection of Pb²⁺ has also reached an acceptable level. Therefore, this convenient strategy has potential application value for on-site rapid detection of Pb²⁺.