▎ 摘　　要

In the present article, nanocomposites of Graphene oxide functionalized organosilane (GO-Silane) based fluorescent biosensor have been developed for the recognition of guanine. Organosilane has been synthesized by the condensation of indole-3-carboxyaldehyde and barbituric acid followed by Cu (I) catalysed azide-alkyne click reaction. The prepared compound was further incorporated into graphene oxide and the interaction and distribution of organosilane and GO-Silane have been analyzed by FT-IR, NMR (H-1 and C-13), XRD, mass spectroscopy and FE-SEM spectral analyses. GO-Silane was then utilized as an efficient emission probe for the recognition of guanine with limit of detection (LOD) value of 39 nM, detection range of 5 mu M-70 mu M and response time of 10 s. The receptor also exhibited high selectivity and sensitivity on addition of different interfering amino acids and the application of this proposed sensing system for urine shows that it has the potential for use in real sample.