Wearable sweat sensors have spearheaded the thrust toward personalized health monitoring with continuous, real-time, and molecular-level insight in a noninvasive manner. However, effective sweat sampling still remains a huge challenge. Here, we introduce an intelligent Janus textile band that bridges the gap between self-pumping sweat collection, comfortable epidemic microclimate, and sensitive electrochemical biosensing via an integrated wearable platform. The dominant sweat sampling configuration is a textile with Janus wettability, which is fabricated by electrospinning a hydrophobic polyurethane (PU) nanofiber array onto superhydrophilic gauze. Based on a contact-pumping model, the Janus textile can unidirectionally and thoroughly transport sweat from skin (hydrophobic side) to embedded electrode surface (hydrophilic side) with epidemic comfort. On-body experimentation reveals that the sensitive detection of multiple biomarkers including glucose, lactate, K + , and Na + is achieved in the pumped sweat. Such smart Janus textile bands can effectively drain epidermal sweat to targeted assay sites via interface modifications, representing a reinforced and controlled biofluids analysis pathway with physiological comfort.
A novel method for determination of diphenylamine (DPA) and its nitrated derivatives, which are considered as characteristic components in smokeless powder and gunshot residues, is described. A tandem mass spectrometric method is established and mass spectrometer parameters optimized for each compound to obtain higher sensitivity. Under optimum conditions, quantitative analysis was carried out. The linear ranges are 5.0-200.0, 2.0-200.0 and 5.0-250.0 ng ml-1 and the detection limits are 1.0, 0.5 and 2.5 ng ml-1 for diphenylamine (DPA), N-NO-diphenylamine (N-NO-DPA) and 4-NO2-diphenylamine (4-NO2-DPA), respectively. Intra-assay and inter-assay precision and accuracy of analysis of these three samples were investigated. Based on the regression lines obtained above, smokeless samples were analyzed. It was found that there are 0.952% DPA, 0.384% N-NO-DPA and 0.128% 4-NO2-DPA in smokeless powder. Recovery tests showed that using cotton swabs, 80.3 +/- 4.9% DPA, 79.6 +/- 3.1% N-NO-DPA and 83.1 +/- 5.4% 4-NO2-DPA could be recovered from human hands.
Sodium sulfinates, sulfinic acids, sulfonyl chlorides and sulfonyl hydrazides as readily available and efficient sulfonylation reagents have been extensively explored in recent years. Sulfonyl radical can be generated from these sulfonyl reagents via different methods, then the sulfonyl radical could react with various substrates via different pathways to afford the corresponding products. In this review, we will summarize the progress in sulfonylation via radical reaction using sodium sulfinates, sulfinic acids, sulfonyl chlorides and sulfonyl hydrazides in recent three years. In terms of the different sulfonylation reagents, we classify these sulfonylation reactions into four types: 1.
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