A pH-Regulated Colorimetric Sensor Array for Discrimination of Biothiols Based on Two Different-Sized β-Cyclodextrin-Functionalized AuNPs

The abnormal changes of biothiols are directly related to health condition of human body,and the effective identification and quantification of biothiols is of great significance for screening and diagnosis of disease.This study described the development of a p H-regulated colorimetric sensor array for discrimination of five kinds of biothiols including cysteine(Cys),glutathione(GSH),homocysteine(Hcy),cysteamine(CA)and N-acetylcysteine(NAC).The proposed sensor array was established using 5-nm-and 20-nm-sizedβ-cyclodextrin-functionalized gold nanoparticles(β-CD@Au NPs)as nonspecific receptor and signal transduction elements.Due to the different binding affinity between biothiols andβ-CD@Au NPs in various p H environments,the different aggregation behaviors of nanoparticles produced unique colorimetric response patterns,which were able to be distinguished by bare eyes and UV-vis spectrophotometer.Accordingly,principal component analysis(PCA)and hierarchical cluster analysis(HCA)were employed for pattern recognition and generated a clustering map for a clear differentiation of biothiols at the level ofμmol/L.Furthermore,it can be proved that the method was successfully applied to the analysis of biothiols in human urine samples.

Optical sensor array for the discrimination of liquors

The discrimination of liquors plays a vital role in our daily life as a large amount of cheap alcoholic beverages and low-quality counterfeits greatly damage the health of consumers.Array-based optical sensors have been developed as a fast and effective tool to discriminate multi-analytes or complex mixtures with similar structures,such as acids,esters,aldehydes and ketones.Over the past decades,optical sensor arrays have demonstrated remarkable capabilities in fast and accurate detection of diverse types,qualities,and authentic liquors.The identification strategy mainly focuses on the specific/non-specific interactions of flavor compounds in liquors with sensor elements.The cross-reactive optical signal readouts from the combination of sensor elements with liquors and multiple machine learning algorithms are essential to ensure the discriminatory capability of sensing system.In this review,we discuss the advantages and recent advances in pattern recognition of liquors in terms of the design of various types of sensing materials and the construction strategies of sensor arrays.