Paclitaxel (PTX), methotrexate (MTX), and 5-fluorouracil (5-FU) are commonly-used small molecule anti-tumor drugs for breast cancer. Unfortunately, drug resistance occurs with long-term treatment or excessive use, and the high concentrations of PTX, MTX, and 5-FU in patients may lead to side effects with dose-limiting toxicities, such as myelosuppression, hepatotoxicity, and peripheral neuropathy. Therefore, concentration monitoring of PTX, MTX, and 5-FU in clinical treatment is very important. We prepared highly sensitive and specific monoclonal antibodies using several haptens, and established a multiple paper-based sensor utilizing optical signals of gold nanoparticles, which simultaneously detected PTX, MTX, and 5-FU in human plasma or urine with 10 min. A portable scanner for quantitative detection in plasma and urine samples was used, and the calculated limit of detection (cLOD) values were 0.002 and 0.142 μg/mL for PTX, 0.187 and 0.976 ng/mL for MTX, and 0.057 and 0.128 μg/mL for 5-FU, respectively. In the recovery test, the recovery rates and the coefficient of variation were 85.84%–108.81% and 1.23%–8.80%, respectively, indicating the reliability and accuracy of the multiple gold immunochromatographic strip (GIS). In addition, for the determination of collected clinical plasma samples, the correlation between the test data of the multiple GIS and liquid chromatography–tandem mass spectrometry (LC–MS/MS) was good. Therefore, the developed multiple GIS could be applied to the rapid detection of PTX, MTX, and 5-FU in different clinical samples.

Antibiotic residues, generated by the irrational use of drugs and environmental pollution, have always been a great challenge to aquaculture safety. Therefore, a quick, convenient, and performance-excellent way to detect antibiotic residues in aquaculture fish is urgently required. In this study, a multiplex immunochromatographic strip biosensor based on gold nanoparticles was developed for the simultaneous detection of five classes of antibiotic residues (24 β-lactam antibiotics, 26 sulfonamides, five tetracyclines, 24 quinolones, and four amphenicols) in aquaculture fish within 10 min. The detection ranges of five representative antibiotics, penicillin G, sulfamethazine, tetracycline, enrofloxacin, and chloramphenicol, were 2.33–38.4, 0.688–17.1, 1.4–48.1, 1.45–32.9, and 0.537–9.06 µg/kg, respectively. The accuracy and stability of these measurements were demonstrated by analyzing spiked fish samples, with recovery rates of 87.5%–115.2% and a coefficient of variation < 9.5%. The cross-reaction rates, based on the five representative antibiotics, were 3.77%–202% for β-lactams, 3.95%–137% for sulfonamides, 9.19%–100% for tetracyclines, 4.9%–145% for quinolones, and 3.2%–100% for amphenicols. The excellent testing performance of the biosensor strip to most of antibiotic residues in aquaculture fish ensures they meet the maximum residue limits required by countries or organizations. Therefore, this multiplex immunochromatographic strip biosensor is potentially applicable to the rapidly on-site determination of antibiotic residues in aquaculture fish.

Triazine herbicides have been widely used in agriculture, but their residues can harm the environment and human health. To help monitor these, we have developed an effective immunochromatographic strip test that can simultaneously detect 15 different triazines in grain samples (including ametryn, cyprazine, atraton, prometon, prometryn, atrazine, propazine, terbuthylazine, simetryn, trietazine, secbumeton, simazine, desmetryn, terbumeton and simetone). Based on our optimization procedure, the visual limit of detection (vLOD) for these triazines was found to be 2–10 ng/mL in assay buffer, and 0.02–0.1 mg/kg in grain samples. Four different grain matrices including corn, brown rice, wheat, and sorghum were studied and the test results showed no significant differences between the 15 triazines analyzed using this method. This test is simple, convenient, rapid, and low-cost, and could be an effective tool for primary screening of triazine residues in grain samples.

In this study, we investigated the in vivo behaviors of chiral cobalt oxide nanoparticles (Co₃O₄ NPs) stabilized with D- or L-cysteine (denoted D- or L-NPs, respectively), as representative chiral metal oxide NPs. Chiral Co₃O₄ NPs exerted no observable cytotoxicity within the tested dose range. Both D-NPs and L-NPs were internalized by dendritic cells through caveola-dependent endocytosis, and L-NPs entered the cells faster than D-NPs. Significantly, a metabolic analysis indicated that chiral L-NPs had the same effect on the level of bile acids in the liver as D-NPs, which is attributed to the almost equal amount of farnesoid X receptor (FXR) induced by the chiral NPs. This study suggests that low chiroptical activity nanomaterials would not affect the metabolism and kinetics under physiological conditions even if there is some difference in their transport.