Resonance light scattering technique for determination of polychlorinated biphenyls with silver nanoparticles

In this paper, a simple and novel method for the determination of polychlorinated biphenyls (PCBs), using silver nanoparticles (AgNPs) as a resonance light scattering (RLS) probe, is proposed. Under optimized conditions, there existed linear relationships between the enhancing RLS intensity of the system and the concentrations of PCBs in the range 8.0 × 10(-8) -1.0 × 10(-6) g mL(-1) for 2,4,4'-trichlorbiphenyl (PCB28), 9.0 × 10(-8) -1.0 × 10(-6) g mL(-1) for 2,2',5,5'-tetrachlorbiphenyl (PCB52) and 4.0 × 10(-8) -1.0 × 10(-6) g mL(-1) for 3,3',4,4'-tetrachlorobiphenyl (PCB77). The corresponding detection limits (S/N = 3) were 2.6 × 10(-8) g mL(-1) for PCB28, 3.3 × 10(-8) g mL(-1) for PCB52 and 6.3 × 10(-9) g mL(-1) for PCB77, respectively. Finally, the mechanism of RLS enhancement was also studied. The results indicated that PCBs were adsorbed on the surface of AgNPs to form larger AgNP-PCB aggregates, resulting in the RLS enhancement of the system.