Drug abuse is seriously endangering human health and jeopardizing society. There is an urgent need for rapid, sensitive, portable, and easy-to-operate methods for the daily detection of drugs in biological matrices. However, current drug detection methods based on chromatography, spectroscopy, immunosorbent assays, etc. are limited by the requirements of high logistical instruments and laboratory. Herein, we proposed a wearable electrochemical aptasensor with high sensitivity and specificity for the direct capture and rapid detection of multiple drugs in sweat. The single aptamer and dual aptamers with different base compositions were designed to compose the aptasensor array. Molecular docking simulations demonstrated different binding affinities between bioamines and aptamers. The developed aptasensor array is shown to be sufficient to generate distinct electrochemical fingerprints for different psychoactive drugs and interfering substances by extracting variable features from electrochemical signals. Sixteen analytes in the same concentration or gradient concentrations were identified with 100% accuracy. In addition, the wearable sensor platform was demonstrated to discriminate various drugs with similar chemical structures in artificial sweat and human sweat samples. The sensor array not only provided a new rapid method for the detection of drugs but also served as a reference for developing wearable sensors for onsite and daily testing of human biochemical information.

A particular sense, touchable gustation, was achieved. We proposed a chemical–mechanical interface strategy with an iontronic sensor device. A conductive hydrogel, amino trimethylene phosphonic acid (ATMP) assisted poly­(vinyl alcohol) (PVA), was employed as the dielectric layer of the gel iontronic sensor. The Hofmeister effect of the ATMP-PVA hydrogel was well investigated to establish the quantitative description of the gel elasticity modulus to chemical cosolvents. The mechanical properties of hydrogels can be transduced extensively and reversibly by regulating the aggregation state of polymer chains with hydrated ions or cosolvents. Scanning electron microscopy (SEM) images of ATMP-PVA hydrogel microstructures stained with different soaked cosolvents present different networks. The information on different chemical components will be stored in the ATMP-PVA gels. The flexible gel iontronic sensor with a hierarchical pyramid structure performed high linear sensitivity of 3224.2 kPa–1 and wide pressure response in the range of 0–100 kPa. The finite element analysis proved the pressure distribution at the gel interface of the gel iontronic sensor and the capacitation–stress response relation. Various cations, anions, amino acids, and saccharides can be discriminated, classified, and quantified with the gel iontronic sensor. The Hofmeister effect regulated chemical–mechanical interface performs the response and conversion of biological/chemical signals into electrical output in real time. The particular function to tactile with gustation percept will contribute promising applications in the human–machine interaction, humanoid robot, clinic treatment, or athletic training optimization.

Photonic crystals (PCs) with fascinating structural color nanomaterials present effectively spontaneous emission modulation and selectively optical signal amplification. Stretchability or elasticity could enable the feasible tunability for structural colors. Aimed at the regulation of structural colors, we endeavored to achieve the PC nanomatrix evolution and optical property during stretching. In this work, a rainbow structural color by stretchable PCs was exploited to provide abundant optical information for multianalyte recognition. The finite element analysis proved the electric field distribution in the PC matrix, which completely matched with the phenomenon of the measured PC spectra. By simply employing analysis of the multistate PC during stretching, the mono PC matrix chip can differentially enhance fluorescence signals in broad spectral regions, resulting in diverse sensing information for high-efficiency multianalysis. The stretchable PC chip can facilely discriminate 14 similar structured saccharides with a minimum concentration of 10–7 M using only one fluorescence complex. Furthermore, saccharides in different concentrations, mixtures, and real samples (beverages and sweets) also can be successfully distinguished. The exploration on fluorescent stretch dependence behavior of the photonic crystal contributes the biomatching optical platform for wearable devices, dynamic environment, clinical, or health monitoring auxiliary.