Zheng Li,Ruohan Zhang,Xiaohui Lu,Luoyu Hu,Xinyu Wang,Wei Liu,Chen Cui,Xuefeng Liu
Photochemical pollutants pose a substantial threat to human health in both outdoor and indoor environments. Herein, we prepare a class of gold nanoparticle-based colorimetric sensor arrays on optimized hydrophobic substrates using a simple pin-printing method for accurate identification and quantification of various gas-phase oxidants, as these microdetectors are low cost, sensitive, and easy to fabricate. For an array of AuNP sensors modified with various thiol-terminated ligands, a unique and distinguishable change in color (i.e., red, green, and blue response patterns) was obtained for each specific pollutant for molecular fingerprinting. Remarkable discrimination among 15 gases at a fairly low vapor concentration (i.e., 500 ppb) was illustrated using standard chemometric methods. Using digital imaging, the AuNP colorimetric sensor array offers ultrasensitive dosimetric identification of gas-phase oxidants relevant to outdoor and indoor air pollution, with limits of detection generally at sub-ppb levels for 2 h measurement. As a practical application, the sensor array is able to predict the overall air quality in indoor office environments over 24 h. Such sensor array based on chemically induced sintering of nanoparticles has significant implications for the development of nanosensors used in continuous monitoring of potential airborne pollutants at low concentrations from a large number of locations in a cost-effective manner.
Background
Flos Chrysanthemi , as a part of Chinese culture for a long history, is valuable for not only environmental decoration but also the medicine and food additive. Due to their voluminously various breeds and extensive distributions worldwide, it is burdensome to make recognition and classification among numerous cultivars with conventional methods which still rest on the level of morphologic observation and description. As a fingerprint spectrum for parsing molecular information, surface-enhanced Raman scattering (SERS) could be a suitable candidate technique to characterize and distinguish the inter-cultivar differences at molecular level. Results SERS spectra were used to analyze the inter-cultivar differences among 26 cultivars of Chinese ornamental Flos Chrysanthemum . The characteristic peaks distribution patterns were abstracted from SERS spectra and varied from cultivars to cultivars. For the bands distributed in the pattern map, the similarities in general showed their commonality while in the finer scales, the deviations and especially the particular bands owned by few cultivars revealed their individualities. Since the Raman peaks could characterize specific chemical components, those diversity of patterns could indicate the inter-cultivar differences at the chemical level in fact. Conclusion In this paper, SERS technique is feasible for distinguishing the inter-cultivar differences among Flos Chrysanthemum . The Raman spectral library was built with SERS characteristic peak distribution patterns. A new method was proposed for Flos Chrysanthemum recognition and taxonomy.
Programmed cell death (PCD) plays a crucial role in the biological processes of living organisms and occurs in various forms, such as apoptosis, necroptosis and ferroptosis. However, traditional methods for PCD analysis are time-consuming and complex. In this paper, we propose a facile surface-enhanced Raman spectroscopy (SERS)-based strategy for the real-time analysis of three PCD patterns utilizing black phosphorus–gold nanoparticles (BP–Au NPs) as the ultrasensitive unlabeled Raman probe. BP–Au NPs, which possess excellent biocompatibility, are capable of detecting dye molecules at concentrations as low as 5 × 1 0 − 8 M and remain stable for at least one week in different physiological environments. In view of this, BP–Au NPs-based SERS technique can distinguish the tiny differences in the molecular fingerprints of cancer cells undergoing three PCD patterns (apoptosis, necroptosis and ferroptosis) triggered by doxorubicin, shikonin and erastin, respectively. We also have real-time monitoring of the intracellular molecular events during PCD, which spy the fluctuations of some typical SERS bands assigned to protein, DNA and lipid, revealing the unique phenotypic characteristics of each PCD pattern. This strategy provides a detailed and comprehensive analysis of the mechanisms of drug-induced PCD at the Raman level.