A novel gold particle-based paper sensor for sensitively detecting carprofen in bovine muscle

A dual-emissive supramolecular sensor for fast and ratiometric determination of carprofen in meat

Carprofen (CPF) is a non-steroidal anti-inflammatory drug that has been widely used in livestock for the treatment of fever and inflammation. Yet the massive use of CPF comes at the cost of its residue ubiquitous in the environment thus leading to a huge risk to human health. Therefore, development of a convenient analytical method for monitoring CPF is of considerable importance. In this study, a dual-emissive supramolecular sensor was facilely constructed using bovine serum albumin as the host and an environmentally sensitive dye as the guest. This sensor, for the first time, successfully realized the fluorescent detection of CPF with a rapid response, high sensitivity and selectivity. More importantly, this sensor exhibited a very unique ratiometric response to CPF, which endowed this method with satisfactory detection accuracy for food analysis. To the best of our knowledge, this is the first fluorescent method for fast determination of CPF in food.

Recent Developments and Applications of Microfluidic Paper-Based Analytical Devices for the Detection of Biological and Chemical Hazards in Foods: A Critical Review

Nowadays, food safety has become a major concern for the sustainability of global public health. Through the production and distribution steps, food can be contaminated by either chemical hazards or pathogens, and the determination of these plays a critical role in the processes of ensuring food safety. Therefore, the development of analytical tools that can provide rapid screening of these hazards is highly necessary. Microfluidic paper-based analytical devices (µPADs) have advanced significantly in recent years as they are rapid and low-cost analytical screening tools for testing contaminated food products. This review focuses on recent developments of µPADs for various applications in the food safety field. A description of the fabrication of selected papers is briefly discussed, and evaluation of the μPADs' performance with regard to their precision and accuracy as well as their limits of detection is critically assessed. The advantages and disadvantages of these devices are highlighted.

Europium nanosphere-based fluorescence strip sensor for ultrasensitive and quantitative determination of fumonisin B1

Contamination of grains and related products by fumonisins (FBs) is increasingly becoming a serious food security issue. The aim of this work was to develop a europium fluorescent microsphere-based time-resolved fluorescence immunochromatographic assay (TRFICA) for FB₁ detection in different grains, including corn, corn flour, wheat, rice and brown rice. Standard curves for the five types of grain matrix were established, and showed good linearity (R² > 0.975), LOD of 8.26 μg kg^-1, and a wide working range of 13.81-1000 μg kg^-1. The recoveries of TRFICA for FB₁ detection ranged from 82.85-103.62% with variation coefficients of 1.92-15.33%. Two corn reference materials and other natural samples were tested using TRFICA. The same samples analyzed by liquid chromatography tandem mass spectrometry further confirmed the TRFICA results. The entire detection time of TRFICA was within 30 min. Thus, this developed TRFICA can be used for onsite detection and quantitation of FB₁ in grains.

Colloidal gold-based immunochromatographic strip assay for the rapid detection of bacitracin zinc in milk

In this study, a murine monoclonal antibody (mAb) of 6D2-G10 against bacitracin zinc (BAC) was produced and applied to an immunochromatographic strip (ICS) for the initial detection of BAC in milk. The ICS with a cut-off value of 25 ng/mL could be perceived by the naked eye within 10 min. With the assist of the strip reader, the limit of detection (LOD) was measured as 0.82 ng/mL, the half-maximal inhibitory concentration (IC₅₀) was recorded as 3.16 ng/mL, and the linear detection range was from 0.97 to 10.30 ng/mL. The recoveries ranged from 87.7% to 96.0% with the highest coefficient of variation (CV) of 9.1% in the intra-assay and from 84.3% to 90.2% with the highest CV of 10.7% in the inter-assay. In short, the established ICS provided a serviceable analytical tool for qualitatively and quantitatively monitoring BAC in milk.