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Buprofezin (BUP) is an effective insecticide against Homopteran and Thysanoptera pests. However, exposure to BUP may result in several harmful effects on the non-target organism including human body, such as hepatotoxicity and DNA damage. Therefore, development of a reliable analytical method for BUP holds paramount importance. This study presents a novel albumin-based supramolecular biosensor, DPP@ALB, designed for the sensitive detection of BUP in environmental matrices, including water, soil, and real food samples. The features of this biosensor include a fast response, high sensitivity, and visually detectable fluorescence color change, enabling on-site detection of BUP based on the portable paper strips and 3D-printed miniaturized testing system. Overcoming challenges associated with the low chemical reactivity of BUP, this supramolecular biosensor emerges as the very first fluorescent sensor for efficient and reliable monitoring of BUP with applications in broader areas of environmental analysis and food safety. • The first ratiometric supramolecular biosensor for the detection of buprofezin. • The response is rapid (< 10 s) and the limit of detection is lower than 0.66 ppm. • Ratiometric response to buprofezin originates from the formation of co-binding albumin complex. • On-site detection of buprofezin has been achieved using a portable sensing device. • This biosensor enables detection of buprofezin in food samples and environmental matrices. [ABSTRACT FROM AUTHOR]

Tetracyclines (TCs) are a group of broad-spectrum antibiotics against multiplying microorganisms yet with several adverse effects on humans. Since all types of TCs have the similar chemical skeleton and mechanism of action, quantification of total amount of TCs in the environment was of particular importance. To date, dozens of fluorescent probes have been reported for TCs detection, but only very few of them enabled detection of total TCs. In this study, we report a novel supramolecular sensor constructed by human serum albumin as the recognition moiety and a flavonol fluorophore as the indicator. Under the 370 nm UV excitation, this sensor exhibits the rapid response (5 s), acceptable sensitivity (limit of detection ∼ 0.58 μM), long dynamic detection range (0–20 μM), prominent specificity, and excellent anti-interference properties for analysis of total TCs. The mechanism was carefully validated using 1H NMR, fluorescence titration experiments, molecular docking, and mass spectrometry. We expect this work can inspire more sensor design for TCs quantification. [Display omitted] • A novel fluorescent sensor enables detection of total amount of tetracyclines. • This method can detect tetracycline with rapid response and high selectivity. • The limit of detection for tetracyclines can reach 0.58 μM. • Accurate detection of total tetracycline in real samples is achieved. [ABSTRACT FROM AUTHOR]

[Display omitted] • This work reported the first ratiometric fluorescent probe for nitroxinil. • The probe enables fast, sensitive and selective detection of nitroxinil. • On-site analysis in real food samples was available by using paper strips. • Fluorescence imaging of nitroxinil in Hela cells was successfully achieved. Nitroxinil (NIT) is a widely using veterinary medicine to protect cattle and sheep yet may threaten human health when ingested through food chain. Developing fluorescent analytical methods in ratiometric manners was essential for the on-site detection and in-situ monitoring of NIT but still challenging. Here, we improved the indicator-displacement assay (IDA)-based method and designed the first ratiometric fluorescent probe for NIT by using an albumin host and an Aggregation-induced emission (AIE) guest. This probe exhibited fast response (10 s), high sensitivity (limit of detection: 4.6 ppb), good selectivity (over twelve medicines) and eye-discriminable fluorescent color change (green–red) upon responding to NIT. Based on these properties, this probe enabled quantitative determination of NIT in real food samples, on-site analysis via a paper-based test strip, and fluorescence imaging of NIT in living cells. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel functional material as the host–guest supramolecular probe was reported. • This work for the first time reported a ratiometric detection method for cyfluthrin. • The probe enables fast, sensitive (LOD 70 ppb), and selective detection of cyfluthrin. • The paper-based testing device was utilized for the smartphone-based analysis. • On-site determination of cyfluthrin in real food samples could be successfully realized. The massive use of cyfluthrin pesticide in agriculture has brought growing concerns on the food safety due to its chemical stability, easy-to-accumulation, and several harmful effects on human health. Design of a rapid, reliable and portable analytical method for on-site monitoring cyfluthrin is of great significance. Although reported assays showed high sensitivity and selectivity to cyfluthrin, these intensity-based outputs suffered from the interference from a variety of analyte-independent factors, i.e. the instrumental parameters, which often led to the poor accuracy and repeatability of detection results. In this work, we reported a novel host–guest supramolecular probe by using albumin as the host and solvatofluorochromic flavonoid as the guest, for the first time, successfully realizing ratiometric determination of cyfluthrin. This probe was capable of detecting cyfluthrin with the fast response (10 s), high sensitivity (LOD ∼70 ppb) and selectivity, good anti-interference performance, and remarkably distinct emission color change from orange to green. Moreover, the portable paper-based test strips could be facilely obtained and utilized for ratiometric determination cyfluthrin pesticide in food samples, such as apple, tomato, cucumber. The signal outputs could be captured and analyzed by using a smartphone, demonstrating the application potential of this probe in on-site food analysis. We expected this work may open up a novel avenue for on-site determination of pesticides with the simple testing apparatuses. [ABSTRACT FROM AUTHOR]

Determination of albuminuria at the point-of-care can provide an early diagnosis and monitor the quality management of numerous diseases. Yet for most fluorescent probes, the detection accuracy is not reliable, since urine itself exhibits very strong endogenous fluorescence causing a considerable interference on response signal. We herein report a novel fluorescent probe DNC with an enhanced environmental sensitivity and red-shifted wavelength (> 600 nm) by enlarging its transition dipole moment. The DNC could selectively bind with drug sites of albumin, causing a significant fluorescence enhancement without the interference from urinary fluorescence. Based on this sensing approach, albuminuria could be directly diagnosed at the point-of-care by using a simple homemade test system (even by naked eyes) without complicate pretreatment of urine. [Display omitted] • A novel fluorescent probe enables determination of albuminuria at point-of-care. • This fluorescent probe can give red-emissive response to albumin without the interference from urinary fluorescence. • The A2-level and A3-level albuminuria can be discriminated by naked eyes using this probe. [ABSTRACT FROM AUTHOR]