Abstract:
In the present report a dihydropyrimidine-based Biginelli compound 1 was engineered into stable organic
nanoparticles via reprecipitation method. The organic nanoparticles, N1 acted as an efficient fluorescent
nanosensor for selective detection of Ag (I) ions via fluorescence quenching with a detection limit of
7.9 nM. Furthermore, successful detection of spermidine (an important biogenic amine) was realized
through an indirect metal ion mediated approach where the quenched fluorescence of complex, C was
recovered with a red-shift on addition of spermidine. The lowest detection limitfor spermidine was found
to be 3.2 nM. The nanosensor found applicability in a wide pH range from 3 to 12, which is appropriate for
evaluation in environmental and physiological conditions. The selectivity for Ag (I) ions and spermidine
was further confirmed with competitive binding studies which demonstrated no interference from other
analytes. Moreover, real sample analysis established the practical applicability of the developed probes.
The proposed strategy provides a facile, non-invasive, sensitive and economic platform for the estimation
of Ag (I) ions in environmental samples (river water) and spermidine in biological samples (urine)
