Biosensors Conference

Abstract

Biosensors involves the design of biomaterials based on electrogenerated polymers, carbon nanotubes and / or nano-objects. Some new approaches for developing nanostructured biomaterials based on functionalized carbon nanotubes, will be briefly described as the compressions of carbon nanotubes, the self-assembly of carbon nanotubes in the form of buckypapers or the creation of hollow electrodes. The self-assembly of carbon nanotubes in the form of conductive sheets (buckypapers) was used to generate bioelectrodes. We, thus, reported the modification of carbon nanotubes with both alkyne-modified diazonium salts and alkyne-modified pyrene followed by photo-irradiated thiol-yne click reaction with thiol-modified redox mediators. The resulting carbon nanotubes achieve the mediated bioelectrocatalytic glucose oxidation by adsorbed FAD-glucose dehydrogenase. Recently, the concept of hollow bioelectrodes based on the bonding of two buckypapers was developed to generate a microcavity defined by the thickness of the glue linking the two sheets. These buckypapers are permeable only to water and enzyme substrates but not allow the permeation of enzymes. The electrocatalytic performance of the bilirubin oxidase hollow electrode was described as a function of pH, temperature and the amount of entrapped enzyme.

Owing to the complexity of optimizing a multienzyme system, this concept also constitutes an attractive strategy to design and optimize enzyme cascade reactions. Besides the easy modulation of enzyme ratios, we have also demonstrated the possibility of trapping with enzymes a redox mediator, HRP and GOx in a buckypaper microcavity.

It is expected that such construction and fast optimization of multienzyme electrochemical systems based on hollow electrodes, will be useful for the development of biosensors.

Abstract

Exosomes are membrane-bound vesicles with a lipid bilayer, ranging in diameter from 30 to 150 nm, which are released into the extracellular environment and enter the circulatory system through the fusion of multivesicular bodies with the cell membrane. Recent studies have demonstrated that exosomes are associated with the onset, progression, and immune response of diseases, making them a new class of biomarkers with broad application prospects. Biochips, characterized by their integration, digitization, and automation, have been widely applied in wearable devices, hospital testing equipment, and the construction of smart healthcare systems in cities. In the field of biochips, this includes two major components: sensors and low-power data transmission. Beyond the chips, it also involves many important aspects related to biomedicine. Therefore, how to integrate all these elements is a significant hurdle for the practical application of biochips. In recent years, to achieve efficient and sensitive exosome detection, point-of-care testing (POCT), especially biosensing, has garnered high attention from scientists and technicians worldwide.

This lecture will focus on combining artificial intelligence and information technology, leveraging the microfluidic sensor platform we have developed in recent years. It will integrate micro-nano fabrication, microelectronics, synthetic biology, digital droplet technology, genome/proteome engineering, and the Internet of Medical Things (IoMT). By synthesizing the vast amount of personalized medical information collected by biosensors, we aim to better predict and prevent the occurrence of various diseases, control their progression, and address the root causes of diseases, thereby helping to establish an intelligent health system for personalized medical connectivity. Several representative intelligent biosensors, including those for infectious diseases and Parkinson’s disease detection, will be introduced as examples.

Abstract

Among the various electronic devices used to translate bioprobe–biotarget interactions into electrical signals, field-effect transistors (FETs) stand out as highly promising. After a brief introduction to the general operating principles of FETs, I will explore electrochemical transistors— both organic (OECTs) and inorganic—as well as electrolyte-gated FETs (EGFETs), which replace the traditional dielectric with an aqueous electrolyte and operate at low voltages (hundreds of mV). These devices are particularly suited for use in biological environments, including in or on living organisms. Their ability to transduce capacitive events at either the electrolyte/semiconductor or gate/electrolyte interface enables a range of biosensing applications. I will illustrate this with examples including antibody–antigen interactions, aptamer–small molecule or protein binding, and detection of charged molecules and metal ions. I will also show that EGOFETs can amplify photocurrents generated by photosynthetic organisms, providing a way to assess pesticide effects in aquatic ecosystems. The critical role of the sensitive interface—especially its interfacial capacitance and size—will be highlighted.

In parallel, printed electronics have advanced significantly, particularly with the emergence of functional inks. Inkjet printing now allows the fabrication of EGFETs under ambient conditions with minimal material waste, offering cost-effective alternatives to traditional photolithography. I will describe the principles of inkjet printing and present examples of transistors and other biosensors produced using this method, with a focus on biomedical applications.

Abstract

This study aimed to investigate the capacitance dependence of NIH/3T3 cells during growth and drug-cell reactions, using impedance biosensor manufactured by semiconductor process.

To address challenges related to scalability, reproducibility, and analytical limitations in conventional impedance biosensors, we developed a multi-well array Electric Cell-substrate Impedance Sensing (ECIS)-based impedance biosensor by integrating array technology with standard ECIS methods. This biosensor enables simultaneous, real-time monitoring of cell growth and drug responses across multiple wells. The consistent responses across wells demonstrate the system’s reliability and robustness.

Furthermore, by applying varying drug concentrations in individual wells, we created an independent 2×2 impedance biosensing environment for drug screening. Using this setup, we successfully performed IC50 (half-maximal inhibitory concentration) analysis to assess drug efficacy. The system revealed that capacitance changes sensitively reflected dose-dependent drug effects, validating the biosensor’s capability for pharmacological studies.

This research presents a novel multi-well array impedance biosensor that combines the advantages of ECIS technology and microarray integration. It offers enhanced throughput, reproducibility, and analytical precision, highlighting its potential as a next-generation platform for drug discovery and biomedical applications.