Kwak, Jisung Kim, Woochul Cho, Hyerim Han, Jiyun Sim, Sang Jun Song, Hyun Gyu Pak, Yusin Song, Hyun Seok 2024-08-08T02:00:15Z 2024-08-08T02:00:15Z 2024-08-08 2024-09 1473-0197 https://pubs.kist.re.kr/handle/201004/150381 Ion channels, which are key to physiological regulation and drug discovery, control ion flux across membranes, and their dysregulation leads to various diseases. Ca2+ monitoring is crucial for cellular signaling when performing Ca-based assays in ion channel research; these assays are widely utilized in both academic and pharmaceutical contexts for drug screening and pharmacological profiling. However, existing detection methods are limited by slow detection speeds, low throughput, complex processes, and low analyte viability. In this study, we developed a label-free optical biosensing method using a conical Au/polydimethylsiloxane platform tailored to detect Ca2+ influx in A549-originated nanovesicles facilitated by the transient receptor potential ankyrin 1 (TRPA1) channel. Nanovesicles expressing cellular signaling components mimic TRPA1 signal transduction in cell membranes and improve analyte viability. The conical Au/polydimethylsiloxane sensor converted Ca2+ influx events induced by specific agonist exposure into noticeable changes in relative transmittance under visible light. The optical transmittance change accompanying Ca2+ influx resulted in an enhanced sensing response, high accuracy and reliability, and rapid detection (similar to 5 s) without immobilization or ligand treatments. In the underlying sensing mechanism, morphological variations in nanovesicles, which depend on Ca2+ influx, induce a considerable light scattering change at an interface between the nanovesicle and Au, revealed by optical simulation. This study provides a foundation for developing biosensors based on light-matter interactions. These sensors are simple and cost-effective with superior performance and diverse functionality. Label-free optical detection of calcium ion influx using nanovesicles: this study presents a conical Au/PDMS biosensor for detecting Ca2+ influx in A549-derived nanovesicles, providing a method for monitoring ion channel activity. English Royal Society of Chemistry Label-free optical detection of calcium ion influx in cell-derived nanovesicles using a conical Au/PDMS biosensor Article 10.1039/d4lc00421c 1 Lab on a Chip, v.24, no.17, pp.4138 - 4146 Lab on a Chip 24 17 4138 4146 Y scie scopus 001278686500001 Biochemical Research Methods Chemistry, Multidisciplinary Chemistry, Analytical Nanoscience & Nanotechnology Instruments & Instrumentation Biochemistry & Molecular Biology Chemistry Science & Technology - Other Topics Instruments & Instrumentation Article DRUG DISCOVERY CHANNELS PROBES TRPA1