Skip to main content
. Author manuscript; available in PMC: 2019 Jul 21.
Published in final edited form as: Analyst. 2018 Jun 20;143(14):3249–3283. doi: 10.1039/c8an00731d

Fig. 2.

Fig. 2

Schematic illustration of crosslinking based colorimetric assays. (A) The detection of bacteriophage T7 using AuNPs modified with covalently bonded anti-T7 antibodies and color change based on antibody antigen interaction which causes them to aggregate [111]. (B) Colorimetric detection of Hg2+ based on chelation reaction between Hg2+ and chitosan and observed color changes in AuNPs [112]. (C) LCR amplification and colorimetric assay of CpG methylation in DNA: In the presence of methylated genomic DNA a red to purple color change can be detected [113]. (D) Colorimetric assay for detection of protein kinase activities based on hybridization between STV-AuNPs and biotinylated peptide (biotin-LRRASLG), and the PKA catalyzed phosphorylation of biotin-peptide prevented AuNPs crosslinking and the monodisperse AuNPs remained red [81]. Reprinted with Permission