Biosensors and Biointerfaces Group - Research Projects

Nanoparticle based biosensors for labelling and detection for medical diagnostics

(with Professor Rose Amal, School of Chemical Engineering, UNSW)
Nanoparticle based biosensors have the distinct advantage over macroscopic biosensors in that they can 1) penetrate into environments normal sensors cannot reach and 2) an ensemble of nanoparticle biosensors can be located throughout an entire sample greater sensitivity and shorter response times are possible. Gold nanoparticles have unique optical properties which makes them excellent labels in biological detection and excellent for nanoparticle biosensors. A simple example is shown below where gold nanoparticles are modified with cysteine to make them selective for Cu(II) in solution. The presence of Cu(II) caused the nanoparticles to aggregate with a concomitant change in colour from red to blue. We are exploring a range of nanoparticle based projects which exploit the expertise of the Amal group in nanoparticle fabrication with our group’s expertise in surface modification and biomolecule immobilisation. Both metal and magnetic nanoparticles are being investigated. This work was funded through the ARC Centre of Excellence for Functional Nanomaterials and is now embanked within the Australian Centre for Nanomedicine.

Cysteine coated gold nanoparticles for copper detection


(Above) - Cysteine coated gold nanoparticles for copper detection. The presence of copper sees a change in colour from red to blue due to particle aggregation with more aggregation the greater the concentration of Cu(II) in solution. TEM images show the unaggregated particles (left) before any exposure to Cu(II) and the aggregated particles (right) after the addition of Cu(II).

For more information on this project see:
W.R. Yang, Z.C. He, J.J. Gooding, G. Chen, Optical Detection of Copper Ions using L-Cysteine Functionalized Gold Nanoparticles, J. Nanosci. Nanotech. 7 712-716 (2007).

I. Goon, L. Lai, M. Lim, P. Munroe, J.J. Gooding, R. Amal, Fabrication and Dispersion of Gold Shell Protected Magnetite Nanoparticles: Systematic Control Using Polyethyleneimine, Chem. Mater. 21 673-681 (2009).

I. Goon, L.M.H. Lai, M. Lim, R. Amal, J.J. Gooding, Dispersible Electrodes: A Solution to Slow Response Times of Sensitive Sensors, Chem. Comm. 46 8821-8823 (2010).