Biosensors Conference

Abstract
We present an integrated smartphone/resistive nanobiosensor for simple, rapid, reagentless, and sensitive detection of OP pesticides in food and environmental water. The biosensor leverages the hydrolytic activity of acetylcholinesterase (AChE) to its substrate, acetylcholine (ACh), and unique transport properties of polyaniline nanofibers (PAnNFs) of chitosan/AChE/PAnNF/carbon nanotube (CNT) nanocomposite film on a gold interdigitated electrode. A mobile app for the biosensor was developed for receiving and analyzing measurement data and displaying and sharing testing results. Under optimal conditions, the biosensor demonstrated a wide linear range (1 ppt–100 ppb) with a low detection limit (0.304 ppt) and high reproducibility (RSD <5%) for Paraoxon-Methyl (PM), a model analyte. Furthermore, the biosensor was successfully applied for analyzing PM spiked food/water samples with an average recovery rate of 98.3% and provided comparable results with liquid chromatography-mass spectrometry. As such, the mobile nanosensing platform open n new avenue for onsite rapid and sensitive monitoring of OP pesticides in food and environmental water. Biography
Jun Wang received his Ph.D. in Analytical Chemistry from Wuhan University, China in 2000 and was subsequently awarded a scholarship from DAAD, Germany (2000-2001). Then, he pursued his postdoc research in the California State University at Los Angeles (LA) and the University of California at LA, respectively (2001-2005). He jointed Pacific Northwest National Laboratory (PNNL) as a scientist (2005-2011). After that, Dr. Wang moved to Charlotte, NC and founded a start-up company (Nanodiagnostic Technology, LLC) in 2011 and served as the president there (2011-present). Since October 2019, Dr. Wang became a Research Professor at the Department of Bioinformatics and Genomics at the University of North Carolina at Charlotte. (APS).

Abstract
Electrochemical chip-based sensors (ECCS) have become a standard method in biosensing of small molecules, as well as more complex structures like immunoassays. Numerous research publications highlight the simplicity, cost-efficiency, and point-of-need applicability of disposable ECCS across various applications. However, their societal uptake remains limited. This is primarily due to reproducibility issues during testing in buffer solutions and the high cost of single-use chips. Moreover, multiple measurements can compromise sensor stability and reproducibility. Specifically, label-free electrochemical impedance spectroscopy (EIS)-based ECCS are susceptible to signal drift, which can result in false-positive or false-negative data, thus questioning the reliability of the measurements. In this talk, I will address the challenges faced with electrochemical sensors in the validation process of sensor performance. I will provide examples of how to select the appropriate electrochemical method and sensor surface to achieve robust and reliable results. I will introduce a novel method for the multiple uses of ECCSs. This method involves incubating the ECCSs in nitrogen-purged, deaerated phosphate-buffered saline (N-PBS) to minimize signal drift in repeated or multiple EIS measurements. This method was subsequently employed to develop a peptide-based EIS biosensor for the detection of Vancomycin, a last-line antibiotic used for treating severe multidrug-resistant bacterial infections using an immunoassay approach. Additionally, this method facilitated the detection of small molecules such as cytokinin, which plays a crucial role in plant root interaction with the soil microbiome for enhanced plant growth. These examples illustrate the versatility and efficacy of the method.

Biography
Winnie Edith Svendsen completed her master degree in experimental physics with honors in 1993 from the University College Dublin, within atomic spectroscopy. She received her doctorate in atomic physics studying the properties of solid deuterium by laser ablation and sputtering in 1996 from Copenhagen University, Denmark. Thereafter she accepted a postdoctoral position at the Max Planck Institute for Plasma physics, Garching, Germany. She returned to Denmark in 1998 and was appointed Associate Professor at Copenhagen University in 1999. Since 2001 she has been involved with applied research and her current research focus is on understanding the physical properties of biological material to optimize the use of micro and nanotechnology in the biomedical field. She was also the co-founder of company XeHe Hypol (APS).

Abstract
Novel sampling and organismal detection systems have been developed to take a larger, more representative sample whose concentrate can be used for DNA/RNA extractions for species detection for better monitoring results to facilitate policy decision. An automated environmental sampler that uses kidney dialysis hollow fibre filters to concentrate all organisms from 25-50 litres into a 1 litre concentrate for downstream DNA/RNA extraction and analysis. The taking of such a large volume of water for any environmental sample provides a much broader picture of the ecosystem to be sampled/monitored. This broader picture will pick up more information on rare events and allow policy decisions to be made based on samples that are more representative of the natural environment than samples of 1 L or less that are now routinely taken by environmental scientists and monitoring agencies. From the concentrated environmental sample, RNA is extracted and used in biosensors with electrochemical detection for toxic algae. Single electrode chips are being developed into a 16-electrode laboratory-on-a-chip. Our long-term goal is to develop an early warning system for toxic algae in a miniaturised laboratory on a chip format with multiplexed electrodes with barcodes for 160 toxic algal species. The barcodes in a single electrode format show a high signal and no cross reactivity when challenged with non-target RNA. Plans are to combine the environmental sampler and the laboratory on a chip into one instrument that will afford real-time monitoring of the environment. We seek collaborations to develop the laboratory on a chip with 144 multiplexed electrodes.

Biography
Professor Linda K. Medlin is currently a Research Fellow at the MBA and CEO Of Algae Save the World, Consulting. Worked previously as Head of Research at Microbia Environnement, France, at the Observatoire Oceanologique of UPMC, France and at the AWI, Germany. Received Ph.D. from Texas A&M University in 1983 in marine botany. Expert in marine phytoplankton evolution/phylogenetics. Published 287 papers, 37 books chapters, two edited books and two special issues, one manual for microarray analysis, 98 invited lectures, of which three are keynote speakers and four are plenary speakers. Awarded 52 research grants of which 19 are EU. 3X winner of the Tyge Christensen award for best paper in Phycologia and 1X winner of the Provasoli award for best paper in Journal of Phycology. Elected foreign member of Norwegian Academy of Science for her pioneering work in phytoplankton phylogenetics. Her 1988 benchmark publication for first PCR primers for 18S gene opened the door for rRNA genes as biodiversity genes. 2022 recipient of the Yasumoto Lifetime Achievement Award given by the International Society for the study of Harmful Algae for her lifetime work on developing phylochips/microarrays/biosensors for early warning systems for toxic algae and freshwater pathogens and for analyzing marine biodiversity. Inventor on three patents for the detection of toxic algae.

Abstract
Since the advent of printed electronics, a new generation of electrochemical printed biosensors has appeared in a variety of applications for rapid and sensitive real-time monitoring and identification of target biomolecules. Of particular interest are flexible disposable biosensors that can be used in healthcare and industrial applications. The growing interest in the realm of printed electronics (PEs) has caused an increase in the number of attempts for accomplishing to design and fabricate practical devices in recent years. These endeavors would provide the manufacturers with low-cost applications and large-scale production. Printed electronics is a multidisciplinary science, as it is a combination of ink chemistry and printing technology.
PEs provide the opportunity of preparing various fast-response sensors based on electrochemical reactions for several analysts and so eliminates the tiring analytical process like sampling, sample preparation, analysis, and data interpretation. The properties of such devices include flexibility, high sensitivity, acceptable selectivity, and good conductivity. Here, different graphene based printed electrodes and their performance as biosensor is reviewed and the obtained results are given and analyzed as flexible electrodes. Besides, other flexible and conductive electrodes based on graphene and the obtained results are also reviewed and the results are presented.

Biography
Saeedeh Mazinani is a faculty member of New Technologies Research Center (NTRC), Amirkabir University of Technology (Polytechnic of Tehran), Tehran, Iran. She is working in the institute as head of nanotechnology group and lab for developing research areas in this field especially polymeric conductive materials. He received my PhD degree in chemical engineering (CREPEC group) from Ecole Polytechnique de Montreal, CANADA; and both B.Sc and M.Sc degrees from polymer engineering department of Amirkabir University of Technology, Tehran, IRAN.