Journal of Analytical & Bioanalytical Techniques
Open Access

Abstract

Gold nanoparticles (AuNPs) have been extensively applied in biosensing field owing to their intrinsic colour and distance- dependent optical properties. While many works have been dedicated on functionalization of AuNPs with biomolecules, the functionalized-AuNPs have limited generalization, as well as requires laborious and costly preparation. In this regard, the unmodified AuNPs may solve the aforementioned problems. The sensitivity of citrates-coated bare AuNPs have been explicitly demonstrated in detecting protein-DNA interaction. Due to the electrosteric protection, the protein-DNA complexes can stabilize the bare AuNPs against salt, better than protein or DNA alone. Herein, we are keen at exploiting the AuNPs? colorimetric response in ligand-induced protein stabilization. It was found that in the presence of stabilizing ligands, the proteins offers greater protection on AuNPs against salt and heat. To validate the new method, two transcription factors, i.e., FoxA1 (forkhead box A1) and AP-2γ (activating enhancer binding protein 2 gamma) were employed, and 14 small ligands selected from National Cancer Institute for assay development. Human serum albumin (HSA) and its three known ligands (ibuprofen, warfarin, and phenytoin) were also used to demonstrate the generality of this method. The results shows good agreement with those obtained from conventional Biacore SPR spectroscopy, differential static light scattering (DSLS) and tryptophan fluorescence spectroscopy. Thus this new assay offers an excellent equipment-free approach to facilitate drug discovery.

Biography

Siu Yee New is an Assistant Professor from the School of Pharmacy, University of Nottingham, Malaysia Campus (UNMC). She received her BSc from University of Technology Malaysia (UTM) and her PhD from National University of Singapore (NUS). During her PhD study, she was involved in multidisciplinary fields with three different research groups and spent a year at University of Illinois at Urbana-Champaign, USA (UIUC). After graduation, she worked as Scientist I in Institute Materials Research and Engineering (IMRE), A*Star, Singapore, before joining UNMC. Her areas of interest stretch across supramolecular chemistry, protein engineering and nanotechnology based biosensors.