Effective and non-invasive inspection method toward viscosity is expected to ease the burden of continued increased health problems worldwide. Herein, we proposed that viscosity is one of the most important markers in the liquid microenvironment. Then, a natural product was further developed from resveratrol derivate, polydatin, as an activatable molecular sensor for monitoring liquid micro-environmental viscosity alterations for metamorphic extent determination. This natural molecular sensor was constructed by the single double bond alternating conjugate structure, which can rotate freely in the low viscosity media, and in the highly viscous media, bright fluorescent signals are specifically activated (around 383 nm, 53-fold), endowing the natural sensor with the capacity to avoid autofluorescence from the additives and achieving high signal-to-noise ratio imaging. With the lower detection limit 1.125 cP, the sensor polydatin exhibits higher viscosity sensitive coefficient (0.60), and 75.5 nm of Stokes shift was found in the distilled water. Afterward, polydatin achieved non-invasively identifying the thickening effects of food thickeners. In addition, the capability of polydatin to evaluate the deterioration extent of liquids with viscosity as a robust marker was explored. It was found that the viscosity level in microenvironments is highly dependent on the liquid food metamorphic period. The fluorescent intensity increment and viscosity value changes were fitted into a linear equation. We expected that this approach would reinvigorate the fluorescent analytical methods toward liquid safety inspection.
Introduction The quantitative analysis of trace resveratrol and polydatin in plant tissues is suitable for elucidation of the compounds' mechanisms of action. Objectives The main objective of this work was to develop a feasible and effective sample pretreatment method to measure the concentrations of resveratrol and polydatin in complex samples. Methodology A polymer sorbent, poly(2-mercaptobenzimidazole), was electrochemically prepared and utilized for selective extraction, while resveratrol and polydatin were used as target analytes. The sorbent was characterized by cyclic voltammetry, scanning electron microscopy and Fourier transform infrared spectroscopy. After extraction and elution, the analytes were analyzed by a Thermo U3000 HPLC system. Several affecting parameters, including the volume of elution solution, sample pH value, sample flow rate and sample volume, were evaluated and optimized. Results The proposed method showed good linearity with low limits of detection (from 0.5 to 0.8 ng·mL −1 ) and ideal accuracy with spiked recoveries from 81.30% to 99.16%. A good enrichment factor (more than 200-fold) together with good sensitivity was obtained with this method. Analysis of resveratrol and polydatin in Polygonum cuspidatum samples by this method is efficient. Conclusion The method developed in this work exhibits several significant merits, including easy operation and high extraction efficiency, indicating that electrochemically prepared polymer sorbent is useful for sample pretreatment and analysis of traditional Chinese medicine samples.
危险品化学品经营许可证（带存储）