Figure 4

UV-vis absorbance spectra of AuNRs solution upon addition of D-Gln (A) or L-Gln (B) (a–j: 0, 0.003, 0.005, 0.01, 0.03, 0.05, 0.07, 0.1, 0.5, 1 mM). Experiment condition: 50 μL AuNRs, 50 μL PBS (pH 6.0), 100 μL D- or L- Gln.