Molecularly imprinted ultrasensitive cholesterol photoelectrochemical sensor based on perfluorinated organics functionalization and hollow carbon spheres anchored organic-inorganic perovskite

Cu2+-doped zeolitic imidazolate frameworks and gold nanoparticle (AuNPs@ZIF-8/Cu) nanocomposites enable label-free and highly sensitive electrochemical detection of oral cancer-related biomarkers

It is of great significance to accurately and sensitively detect oral cancer-related biomarkers (ORAOV 1) for the early diagnosis of oral cancer. Present here is a novel electrochemical biosensor based on Cu2+-doped zeolitic imidazolate frameworks and gold nanoparticle (AuNPs@ZIF-8/Cu) nanocomposites and a one-step strand displacement reaction for label-free, simple and sensitive detection of ORAOV 1 in saliva. It is worth noting that AuNPs@ZIF-8/Cu nanocomposites show large electrochemically effective surface area, good electrical conductivity and electrocatalytic activity due to the synergistic effect of metal nanoparticles (MNPs) and ZIF-8. Consequently, the newly developed electrochemical sensor displays a wide linear range of 0.1-104 pM and a low limit of detection (LOD) of 63 fM. Meanwhile, the electrochemical biosensor can distinguish single base mismatch. The relative standard deviation (RSD) of intra-assays and inter-assays is 1.46% and 1.76%, respectively, and the peak current values decline by 9.20% with a RSD value of 1.35% after being stored at 4 °C for 7 days, suggesting that the newly designed electrochemical sensor exhibits good selectivity, reproducibility and stability to detect ORAOV 1. More importantly, this novel electrochemical sensor is found to be applicable for detecting ORAOV 1 in human saliva samples with a satisfactory result. The RSD values range from 1.15% to 1.77%, and the recoveries range from 95.46% to 112.98%.

A Novel Dual Bacteria-Imprinted Polymer Sensor for Highly Selective and Rapid Detection of Pathogenic Bacteria

The rapid, sensitive, and selective detection of pathogenic bacteria is of utmost importance in ensuring food safety and preventing the spread of infectious diseases. Here, we present a novel, reusable, and cost-effective impedimetric sensor based on a dual bacteria-imprinted polymer (DBIP) for the specific detection of Escherichia coli O157:H7 and Staphylococcus aureus. The DBIP sensor stands out with its remarkably short fabrication time of just 20 min, achieved through the efficient electro-polymerization of o-phenylenediamine monomer in the presence of dual bacterial templates, followed by in-situ template removal. The key structural feature of the DBIP sensor lies in the cavity-free imprinting sites, indicative of a thin layer of bacterial surface imprinting. This facilitates rapid rebinding of the target bacteria within a mere 15 min, while the sensing interface regenerates in just 10 min, enhancing the sensor's overall efficiency. A notable advantage of the DBIP sensor is its exceptional selectivity, capable of distinguishing the target bacteria from closely related bacterial strains, including different serotypes. Moreover, the sensor exhibits high sensitivity, showcasing a low detection limit of approximately 9 CFU mL-1. The sensor's reusability further enhances its cost-effectiveness, reducing the need for frequent sensor replacements. The practicality of the DBIP sensor was demonstrated in the analysis of real apple juice samples, yielding good recoveries. The integration of quick fabrication, high selectivity, rapid response, sensitivity, and reusability makes the DBIP sensor a promising solution for monitoring pathogenic bacteria, playing a crucial role in ensuring food safety and safeguarding public health.