Research in Professor Yan’s laboratory focuses on Environmental Analytical Chemistry, Bioanalytical Chemistry, and Advanced Materials Based Analytical Chemistry.

Interest in environmental analytical chemistry involves the development of novel hybrid techniques for speciation  analysis of trace elements, flow injection (FI) on-line sorption  preconcentration and separation techniques coupled with atomic (mass)  spectrometry, and green methodologies of sample preparation for the  analysis of persistent toxic substances (PTS). Recent developments  include several novel hybrid techniques based on capillary  electrophoresis (CE) and atomic spectrometry for speciation analysis,  such as CE on-line coupled with atomic fluorescence spectrometry (AFS),  chip-CE on-line coupled with AFS, CE on-line coupled with flame heated  quartz furnace atomic absorption spectrometry, and short column CE  on-line coupled with inductively coupled plasma mass spectrometry  (ICPMS). Significant advantages of these hybrid techniques include their simplicity, readily availability, low instrument and running costs,  easy operation, high sensitivity and selectivity. A simple and effective approach, named displacement solid-phase extraction, was also proposed  for selective FI sorption preconcentration and separation of heavy  metals and their species from complex matrices. Several novel  solid-phase microextraction (SPME) fibers/coatings, were also developed  for analysis of PTS.

Research in bioinorganic analytical chemistry concentrates on the development of novel techniques to study metal  species-biomolecule interactions, and metallomics. Recent representative works include the development of a new hybrid technique, CE on-line  coupled with electrothermal atomic absorption spectrometry (CE-ETAAS),  and its application to studying the thermodynamics and kinetics for  interactions between mercury species and DNA or HSA, Cd²⁺ and DNA, and application of CE-ICPMS to studying the competitive binding of Zn²⁺ against Cd²⁺ for glutathione.

Interests in advanced materials based analytical chemistry include the synthesis and applications of quantum dots (QDs),  molecularly imprinted materials (MIPs), carbon nanotubes (CNTs),  graphene, metal-organic frameworks (MOFs), and metal nanoparticles for  selective extraction and separation, bioimaging, sensing, and detecting  of environmentally and biologically important targets. Recently, a room  temperature ionic liquid mediated non-hydrolytic sol-gel methodology to  prepare molecularly imprinted silica-based hybrid monoliths was  developed for chiral separation in this lab. This approach avoids the  cracking and the shrinkage of the bed during drying associated with the  conventional hydrolytic sol-gel process, overcomes the shortcomings  associated with conventional organic polymer-based MIP matrices, and  offers improved selectivity. Recent research also includes the  exploration of Mn-doped ZnS QDs for room temperature phosphorescent  sensing, development of several QDs-based systems for bioimaging and  optosensing application, CNTs coated fibers for SPME, MIPs for selective solid-phase extraction and sensing, and biomolecules functionalized  CNTs for selective removal of heavy metals.