ACS Sensors最新文献

This paper presents a platform for amyloid-β (Aβ) biosensors, employing nearly monolayer semiconducting single-walled carbon nanotubes (sc-SWNTs) via click reaction. A high-purity sc-SWNT ink was obtained by employing a conjugated polymer wrapping method with the addition of silica gel. Aβ detection involved monitoring the electrical resistances of the sc-SWNT layers. Electrical resistances increased rapidly corresponding to the concentration of amyloid-β 1-42 (Aβ1-42) peptides. Furthermore, we introduced Aβ peptides onto the 1-pyrenebutanoic acid succinimidyl ester (PBASE) linker, confirming that only the chemical adsorption of the peptide by the antibody-antigen reaction yielded a significant change in electrical resistance. The optimized sensor exhibited a high sensitivity of 29% for Aβ at a concentration of 10 pM. Notably, the biosensor platform featuring chemically immobilized sc-SWNT networks can be customized by incorporating various bioreceptors beyond Aβ antibodies.

Transcription factor (TF)-based biosensors (TFBs) have received considerable attention in various fields due to their capability of converting biosignals, such as molecule concentrations, into analyzable signals, thereby bypassing the dependence on time-consuming and laborious detection techniques. Natural TFs are evolutionarily optimized to maintain microbial survival and metabolic balance rather than for laboratory scenarios. As a result, native TFBs often exhibit poor performance, such as low specificity, narrow dynamic range, and limited sensitivity, hindering their application in laboratory and industrial settings. This work analyzes four types of regulatory mechanisms underlying TFBs and outlines strategies for constructing efficient sensing systems. Recent advances in TFBs across various usage scenarios are reviewed with a particular focus on the challenges of commercialization. The systematic improvement of TFB performance by modifying the constituent elements is thoroughly discussed. Additionally, we propose future directions of TFBs for developing rapid-responsive biosensors and addressing the challenge of application isolation. Furthermore, we look to the potential of artificial intelligence (AI) technologies and various models for programming TFB genetic circuits. This review sheds light on technical suggestions and fundamental instructions for constructing and engineering TFBs to promote their broader applications in Industry 4.0, including smart biomanufacturing, environmental and food contaminants detection, and medical science.

The development of stimulus-responsive and amplification-based strategies is crucial for achieving improved spatial specificity and enhanced sensitivity in tumor molecular imaging, addressing challenges such as off-tumor signal leakage and limited biomarker content. Therefore, a cyclically activated enzymatic biosensor based on the modification of an AP site within a tetrahedral framework DNA (AP-tFNA) was rationally developed for tumor cell-specific molecular imaging using the endogenous enzyme apurinic/apyrimidinic endonuclease 1 (APE1) as a target, exhibiting superior spatial specificity and high sensitivity. APE1, which predominantly localizes within the nucleus in normal cells but exhibits cytosolic and nucleus expression in cancer cells, can specifically recognize and cleave the AP site in AP-tFNA, resulting in the separation of the fluorophore and quenching group, thereby inducing a fluorescence signal. Additionally, upon completion of the excision of one AP site in AP-tFNA, APE1 is released, thereby initiating a subsequent cycle of hydrolytic cleavage reactions. The experimental results demonstrated that AP-tFNA enables precise differentiation of tumor cells both in vitro and in vivo. In particular, the AP-tFNA can monitor drug resistance in neuroblastoma cells and classify the risk for neuroblastoma patients at the clinical plasma level.