Research on plasmonics and their applications in diverse fields has increased significantly over the last decade. The present work primarily aimed to bio-fabricate silver and gold plasmonic nanoparticles and to study their potential as photocatalysts and as DNA binders. To achieve this, Ag and Au NPs were derived employing Peristrophe paniculata and their optical, morphological and structural properties were investigated by standard analytical techniques. The formation rate constant k was 2.58x10(-2) min(-1) and 3.56x10(-2) min(-1) for Ag and Au NPs correspondingly. FT-IR analysis showed that the water-soluble alkaloid, 5-amino-3,4-dihydro-2H-pyrrole-2-carbonitrile was responsible for the stabilization of nanoparticles. Transmission electron microscopic studies disclosed the formation of uniform spherical AgNPs and irregularly shaped AuNPs and the diameter was 9.32 nm and 27.85 nm respectively which was again corroborated by XRD studies (16.64 nm and 36.08 nm). The interaction of ct-DNA with Ag and Au NPs was investigated using absorption spectroscopy in the UV-Vis range and the binding constant values were 2.2x10(5) M-1 and 8.1x10(6) M-1 respectively. The degradation of methylene blue and malachite green by AgNPs was almost 100 % and 65 % respectively in 3 h under sunlight and neutral pH (pseudo first order rate constants were 7.9x10(-3) min(-1) and 1.9x10(-3) min(-1)). Moreover, the derived AgNPs exhibited mitigate activity against targeted pathogens. Thus, this green technique could be implicit for the eco-friendly synthesis of Ag and Au NPs, and the prepared nanoparticles may be explored as photocatalysts for the degradation of cationic dyes without any added oxidants.