A mononuclear zinc(II) carboxylate complex containing 4-hydroxybenzoic acid and N-donor 2-aminopyridine was synthesized in aqueous methanol and comprehensively characterized by elemental, spectroscopic, and single-crystal X-ray diffraction analyses. The complex crystallized in monoclinic space group P21/c having a distorted square pyramidal structure. Spectral and X-ray diffraction analyses confirm the molecular composition of the complex. The complex has shown strong fluorescence emission, acts as a selective and sensitive chemosensor for nitroaromatics. The complex is able to selectively detect picric acid in the presence of other nitroaromatics. Density Functional Theory (DFT) calculations further elucidate the complex’s preferential binding towards nitroaromatics, revealing the involvement of π-stacking and spodium bonding interactions. This work not only expands the understanding of zinc(II) carboxylate complexes in supramolecular chemistry but also highlights their promising applications in environmental monitoring and biological studies due to their significant fluorescence quenching in the presence of nitroaromatics and moderate DNA binding affinity.