Gold nanorods (GNRs) modified with functional molecules are useful in chemical and biological sensing. In this work, the extinction spectrum of purified GNRs prepared by seed-mediated growth is systematically characterized by UV-visible absorption spectroscopy to test its stability before and after alkane-thiol modification. The results show that purification of GNRs makes the GNRs less stable, while a GNRs colloid solution functionalized by 11-mercaptoundecanoic acid (MUA), 3,3′-dithiobis[6-nitrobenzoic acid]bis(succinimide)ester (DSNB), or 16-mercaptohexadecanoic acid (MHA), respectively is stable over time. Bovine serum albumin (BSA) as a sample protein can be successfully attached to DSNB modified GNRs and form stable BSA-DSNB-GNRs probes. The red-shift observed in the extinction spectrum due to the BSA attachment is consistent over repeated experiments. Finally, anti-PSA (prostate-specific antigen) as a capture antibody is also attached to DSNB-modified GNRs. The attached anti-PSA is capable of interacting with prostate-specific antigens and induces a further red-shift, suggesting potential applications of thiol modified GNRs in bio-sensing.
ASJC Scopus subject areas
- Chemical Engineering(all)