Jingjuan Xu

Professor, College of Chemistry and Chemical Engineering, Nanjing University

Summary of my work

  1. Study of micro-nanofluidic integrated system for bioanalysis: This project focuses on the study of mass/charge transfer behaviors in micro-nano channels and inestablishing theoretical models, such as the modulation and control of the mass transfer in micro/nano fluidic systems as a result of changing the characteristics of micro/nano channel surfaces and performing highly efficient accumulation techniques for biomacromolecules. It also addresses the combination of electrophoresis separation with highly sensitive electrochemical methods to fabricate a micro/nano fluidic platform with the integration of injection, accumulation, reaction, and separation and detection units.
  2. Study of highly sensitive semi-conductor nanocrystal ECL (electrogenerated chemiluminescence) biosensors: The research on this topic is in the beginning stages because there have been a series of problems in the process of fabricating highly sensitive biosensors. To address these problems, we are proposing that this project be based on our previously established ECL energy transfer methods. They focus on studying the energy transfer mechanisms between the labels (such as gold nanoparticles and magnetic nanoparticles) and semiconductor NCs, establishing highly sensitive ECL detection methods for biological macromolecules; further developing energy fitting ECL active materials; full exploring the mechanism of the exciton-Plasmon interaction, the effect of magnetic field on the ECL of magnetic semiconductor NCs and the application possibility of magnetic nanoparticles as biolabels in the ECL energy transfer technique. It is anticipated that this approach will yield a new detection technique and platform for bioscience research.

Both projects closely relate to my work at Cornell in analytical biotechnology, where chemical and biological techniques are combined and integrated into innovative and engineered devices for the detection of biological and chemical substances in the environment, food, and medicine.

Impacts in China

Our projects are focused on using nanoscale gold membrane electrodes for constructing sensors for the determination of metal ions in soils and water. In China, large areas of soil and water have been contaminated with metal ions due to increasing urbanization and industrialization. Generally, soil and water samples are collected in the field and then analyzed in a laboratory. Developing portable and sensitive sensors for quick in-field determination of metal ions is urgently needed. We have successfully developed As(III) and Pb2+ sensors, based on nanoscale gold modified electrode, with a high sensitivity of 0.1M for Pb2+ and 0.04 ppb for As(III).