@article{hetzler_wang_krafft_jamalzadegan_overton_kudenov_ligler_wei_2022, title={Flexible sensor patch for continuous carbon dioxide monitoring}, volume={10}, ISSN={["2296-2646"]}, DOI={10.3389/fchem.2022.983523}, abstractNote={Monitoring and measurement of carbon dioxide (CO2) is critical for many fields. The gold standard CO2 sensor, the Severinghaus electrode, has remained unchanged for decades. In recent years, many other CO2 sensor formats, such as detection based upon pH-sensitive dyes, have been demonstrated, opening the door for relatively simple optical detection schemes. However, a majority of these optochemical sensors require complex sensor preparation steps and are difficult to control and repeatably execute. Here, we report a facile CO2 sensor generation method that suffers from none of the typical fabrication issues. The method described here utilizes polydimethylsiloxane (PDMS) as the flexible sensor matrix and 1-hydroxypyrene-3,6,8-trisulfonate (HPTS), a pH-sensitive dye, as the sensing material. HPTS, a base (NaOH), and glycerol are loaded as dense droplets into a thin PDMS layer which is subsequently cured around the droplet. The fabrication process does not require prior knowledge in chemistry or device fabrication and can be completed as quickly as PDMS cures (∼2 h). We demonstrate the application of this thin-patch sensor for in-line CO2 quantification in cell culture media. To this end, we optimized the sensing composition and quantified CO2 in the range of 0-20 kPa. A standard curve was generated with high fidelity (R2 = 0.998) along with an analytical resolution of 0.5 kPa (3.7 mm Hg). Additionally, the sensor is fully autoclavable for applications requiring sterility and has a long working lifetime. This flexible, simple-to-manufacture sensor has a myriad of potential applications and represents a new, straightforward means for optical carbon dioxide measurement.}, journal={FRONTIERS IN CHEMISTRY}, author={Hetzler, Zach and Wang, Yan and Krafft, Danny and Jamalzadegan, Sina and Overton, Laurie and Kudenov, Michael W. and Ligler, Frances S. and Wei, Qingshan}, year={2022}, month={Sep} }
 @article{skolrood_wang_zhang_wei_2022, title={Single-molecule and particle detection on true portable microscopy platforms}, volume={4}, ISSN={["2666-0539"]}, DOI={10.1016/j.snr.2021.100063}, abstractNote={Point-of-care technologies (POCT) that enable early disease detection and therapeutic monitoring are crucial for the next generation of diagnostics and personalized medicine. Meanwhile, there is a global need for low-cost POCT that makes advanced diagnostic tools accessible to resource-limited settings. Recently, several mobile imaging platforms for single-molecule and particle detection have been developed, which greatly improve the detection sensitivity of molecular assays. This review highlights emerging technologies that achieve single-molecule and particle optical detection on true portable platforms. Miniature, high-sensitivity imaging devices based on smartphones, single-board computers (i.e., Raspberry Pi systems), lab-on-a-chip systems, and 3D-printed microscopy platforms are discussed.}, journal={SENSORS AND ACTUATORS REPORTS}, author={Skolrood, Lydia and Wang, Yan and Zhang, Shengwei and Wei, Qingshan}, year={2022}, month={Nov} }
 @misc{wang_zhang_wei_2021, title={Smartphone videoscopy: Recent progress and opportunities for biosensing}, volume={10}, ISSN={["2192-8584"]}, url={https://doi.org/10.1515/aot-2021-0009}, DOI={10.1515/aot-2021-0009}, abstractNote={Abstract Smartphone is emerging as a portable analytical biosensing platform in many point-of-care (POC) applications such as disease diagnostics, environmental monitoring, and food toxin screening. With the recent advancement of imaging technologies on the smartphone, the manual control of acquisition settings (e.g., exposure time, frame rate, focusing distance, etc.) has already been expanded from the photo to the video capturing mode. In modern smartphone models, high frame rate (above 100 fps) can be achieved to bring in a new temporal dimension to the smartphone-supported POC tests by recording high-definition videos. This opens up a new analytical method defined as smartphone videoscopy. In this review, the recent development of smartphone videoscopy is summarized based on different POC applications. Representative examples of smartphone videoscopy systems and how these time-dependent measurements could open up new opportunities for POC diagnostics are discussed in detail. The advances demonstrated so far illustrate the promising future of smartphone videoscopy in biosensing, POC diagnostics, and time-resolved analysis in general.}, number={2}, journal={ADVANCED OPTICAL TECHNOLOGIES}, publisher={Walter de Gruyter GmbH}, author={Wang, Yan and Zhang, Shengwei and Wei, Qingshan}, year={2021}, month={Apr}, pages={123–138} }