Fig. 7From: SERS Detection of Biomolecules by Highly Sensitive and Reproducible Raman-Enhancing Nanoparticle Array a SERS spectra of β-carotene at different concentrations (from 0.31 to 20 ppm). b Integrated area of 1416 cm−1 peak of adenine (\( {I}_{1416}^{*} \)) as a function of concentrationBack to article page