Rapid and sensitive colorimetric detection of Salmonella in food samples remains challenging. Herein, we developed a preamplification-free colorimetric platform for sensitive detection of Salmonella by integrating whole-cell bio-barcode immunoassay with a Cas12a-gated HCR/G-quadruplex DNAzyme cascade. In this system, target bacteria were immunomagnetically separated and labeled with barcode DNA-modified AuNPs, which converted bacterial cells into abundant Cas12a-activating DNA signals. The activated Cas12a subsequently regulated the HCR/G-quadruplex DNAzyme system, leading to a target-dependent colorimetric response. Benefiting from efficient whole-cell enrichment, bio-barcode signal transduction, and enzyme-free DNAzyme amplification, the proposed method enabled sensitive colorimetric detection of Salmonella with a detection limit of 13 CFU mL −1 and a practical linear range of 10 2 –10 6 CFU mL −1 . Moreover, the platform exhibited good specificity and was successfully applied to Salmonella detection in artificially spiked milk and chicken samples, supporting its feasibility in complex food matrices. Owing to the programmability of barcode DNA and CRISPR/Cas12a, this strategy provides a preamplification-free route for colorimetric detection of foodborne pathogens.
Endocrine-disrupting compounds (EDCs), particularly bisphenol A (BPA) and dibutyl phthalate (DBP), have garnered significant attention due to their widespread presence in the environment and food sources, as well as their potential adverse effects on human health and ecosystems. Many studies have employed selective extraction processes using molecularly imprinted polymers (MIPs). However, conventional MIPs have limited access to their recognition sites due to slow mass-transfer kinetics. Therefore, stimulus-responsive MIPs (SR-MIPs) have been developed to enable reversible adsorption and controlled desorption in response to external stimuli, such as solvents, pH, temperature, photo, and other factors. Although numerous reviews have discussed the development of MIPs and SR-MIPs, along with their applications in analyzing various sample types, none have specifically addressed SR-MIPs for endocrine-disrupting chemicals, particularly bisphenol A (BPA) and dibutyl phthalate (DBP). Therefore, this review aims to provide an overview of the studies published from 2014 to 2026 on the development of SR-MIPs for BPA and DBP. This review discusses the synthesis strategy, adsorption performance, selectivity, and applications in various samples.
On-site quantification of airborne biological agents with low latency is critical for mitigating infection risks, informing ventilation strategies, and enabling rapid responses in high-risk environments. However, most existing aerosol detection approaches rely heavily on off-site laboratory analysis, which limits temporal resolution and hinders early intervention. Here, we report an automated interferential plasmonic system (AIPS) that integrates programmable aerosol collection, embedded microfluidic sample processing, sensitive and specific plasmonic sensing, and fully automated workflow control for in situ detection of bioaerosol.The AIPS combines a humidity-regulated condensation-growth module with an inertial liquid-impingement sampler to achieve high-efficiency capture of coarse and submicron biological particles, followed by an in situ lysis process to release intracellular nucleic acid components from microorganisms. An interferential nano plasmonic assay is subsequently employed to quantify the concentration of target biological agents with high specificity. The system achieves a practical detection limit in the collected liquid and completes the entire “air-sampling-to-result” label-free quantification process within 90 min (30 min sampling and 60 min processing and detection), along with a label-free alarm to target presence as fast as 1 min after completing the air sample. Integration of amplification methods can further enhance sensitivity and support more accurate detection across a wide range of scenarios. Real-world pilot measurements demonstrate that the AIPS enables high-spatiotemporal-resolution monitoring of indoor and outdoor bioaerosol dynamics and supports quantitative exposure assessment. This work establishes AIPS as a next-generation platform for continuous, autonomous surveillance of airborne biological threats and provides a promising solution for early warning of infection risks in healthcare, transportation, and other public environments.
