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An on-site direct detection method for paraquat in biologic fluids was developed on the basis of iodidefacilitated pinhole shell-isolated nanoparticle-enhanced Raman spectroscopy. A full removal of matrix interference on the nanoparticle surface from the complicated biologic samples, and a selective attraction of paraquat to "hotspot" via a highly electrostatic adsorption on the iodide-modified nanoparticle surface are accomplished in this method. Four distinguished characteristics were provided as (1) high sensitivity with a limit of detection of 1 mg L À1 for paraquat; (2) free of pretreatment with a direct measurement in plasma or urine finished within 1 minute; (3) on-site detection using a portable Raman spectrometer; and (4) high antifouling stability during measurement with the pinhole shellisolated nanoparticle structure. This method was further showed its great clinical diagnosis applicability on a rapid, accurate detection of the plasma and urine samples from a paraquat poisoned patient. Fig. 5 SERS spectra of the urine (a) and plasma (b) of the paraquat poisoned patient and of saline solution (c). Both urine and plasma samples were diluted 100 times by saline solution.This journal is

Cyanide is a great threat to public health, environmental safety and homeland security because of its extremely high toxicity and widespread usage in industry. Countering such a threat can be greatly aided by a rapid, sensitive, on‐site detection method. Here, a pinhole shell‐isolated nanoparticle‐enhanced Raman spectroscopy (SHINERS) technique for cyanide sensing has been established, and a limit of detection lower to 1 µg l−1 level in water was achieved on a portable Raman spectrometer, owing to the magnificent local electromagnetic field enhancement generated by the interaction between cyanide anion and the uncovered Au surface inside the pinholes. Meanwhile, the silica shell outside the Au core could significantly improve the stability of the substrate by preventing the dissolution of Au in cyanide solution, thereby making this assay more feasible for practical use. The linear range was from 1 to 100 µg l−1 with excellent selectivity over thiocyanide and other common ions. For applications on complex matrices such as polluted water, beverages etc., a simple online hydrogen generator was designed and successfully coupled with pinhole SHINERS to achieve a good measurement of cyanide. This pinhole SHINERS‐based method is rapid, simple, with good stability and feasibility for the in‐field detection of cyanide, and we hope that it will further raise more opportunities for portable SERS applications. Copyright © 2014 John Wiley & Sons, Ltd.

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Nerve agents (NAs) are notorious chemical warfare agents that pose a serious threat to national security and public health. The total number of theoretical chemicals of NAs and their degradation products (DPs) exceeds 410 000, according to 1.A.01–1.A.03 in the Schedules of Chemicals of the Chemical Weapons Convention, which poses great challenges for identification and verification. A three-step integrated untargeted screening strategy was developed based on high-resolution mass spectrometry. First, an extensible homemade library for targeted screening of common classical agents was established. Second, a set of in-source collision-induced dissociation mass spectrometry (MS)-alerting ions was extracted and concluded based on fragmentation behavior studies, which included 40 specific alerting ions and 10 types of characteristic structural fragments from total NAs and their DPs. A novel “alerting ion” searching method was developed to rapidly and sensitively screen whether or not nerve agent-related compounds were present and of which type they were. Third, we built a theoretical exact mass database including 202 accurate masses or molecular formulas, which could cover all structural possibilities of the NAs and their DPs. Comprehensively, the elemental composition of pseudomolecular ions, fragment ions, MS/MS spectra, and isotope pattern information were obtained from the full scan MS/data dependent-MS2 experiments and elucidated for identification of the candidates selected in the screening step. This strategy was successfully applied to the identification of unknown chemicals in real samples with good stability and a low limit of detection of 1–10 ng/mL. These procedures are applicable for trace forensic investigations in cases of the alleged use of nerve agents.

Fentanyl and morphine are opioid drugs as well as new psychoactive substances. Even originally introduced as efficient anesthetic drugs to relieve moderate‐to‐severe pain in clinic, the overdose of new synthetic opioids is currently a serious public health problem in numerous countries worldwide. The entire category of fentanyls has been included in the regulatory list in several countries. There is a great and urgent demand to rapidly recognize fentanyls and morphines in various samples. Here, we report an on‐site surface‐enhanced Raman spectroscopic method to classify fentanyls from morphines by the Raman spectroscopic signature of the molecular scaffold structure, with an assistance of principle component analysis algorithm. Moreover, by simple but fine‐tuning approach of inorganic salt‐induced aggregation of gold nanoparticles substrate, we achieved a selective detection of 10 ng/mL fentanyl from 2000‐fold of heroin, the most common coexisting substance in chemical samples. Good differentiation of 50 ng/mL fentanyl from 10 000‐fold morphine as a main metabolite of heroin in urine samples was also possible after a feasible pretreatment by StageTip procedures. Depending on different structures, the detection sensitivity of five fentanyls ranged from 50 to 2000 ng/mL.

Phosgene and its analogs are greatly harmful to the public health, environmental safety and homeland security as widely used industrial substances with extremely high toxicity. In order to rapidly evaluate the emergency risk caused by these chemicals, a new highly sensitive method based on surface-enhanced Raman spectroscopy (SERS) technique for measurement of phosgene agents was developed for the first time. Coupled with a chemical transformation approach, the highly toxic phosgene was conveniently converted to a SERS-sensitive probe, i.e. iodine (I 2 ), with low toxicity or non-toxicity. The characteristic SERS peak in 459 cm À1 was used for quantitation and was presumed as a formation of triiodide anion (I 3 À ), which was induced in an iodide (I À )-aggregation Au NPs system. The total measurement can be completed in~20 min with the limits of detection of~60 μg/l (phosgene) and~30 μg/l (diphosgene), respectively, on a portable Raman spectrometer. This work is the first report of SERS measurement on phosgene and diphosgene in a quantitative level. This method is expected to meet the requirements of on-site detection of phosgene agents, promote emergency responses and raise more opportunities for the portable SERS applications.