Detection of manganese (II) by PVP-AgNPs for water monitoring
摘要
Urbanization and human activities have led to manganese (II) entering water bodies from various sources. Excessive discharge of manganese (II) in water may lead to several life-threatening diseases so the detection of manganese (II) for water monitoring is an emerging area of concern. This work aims to use polyvinyl pyrrolidone capped silver nanoparticles (PVP-AgNPs) as a sensing agent for cost-effective, rapid and facile colorimetric detection of manganese (II) in water. PVP-AgNPs were synthesized using the chemical reduction method. Manganese (II) caused PVP-AgNPs to aggregate, changing their color from yellow to brown (0 to 5 × 10−5 M), blackish brown (6 × 10−5 M to 3 × 10−4 M) and cordovan red (4 × 10−4 M to 1 × 10−3 M) linked to the red-shift observed in their localized surface plasmon resonance (LSPR) peak at λmax = 402 to 580 nm. Moreover, dynamic light scattering and transmission electron microscope (TEM) verified the aggregation of PVP-AgNPs. The LSPR-based approach for detecting manganese (II) has a linear detection range of 2 × 10–5 to 8 × 10−5 M, with a 2.82 × 10−7 M limit of detection (LOD). Recoveries were adequate, being in the acceptable range of 91.2–99% and relative standard deviation (RSD) of < 4.73% for real samples. The developed method was then compared with the standard persulphate method and showed less %error in analysis. The results indicated that the developed detection method was selective, sensitive and user-friendly.