Efficient chemiluminescence by aptamer – reactant platform combination with activated Ag–Au alloy nanoparticles for cobalt detection

Abstract

ABSTRACTThis article deals with the detection of Co(II) in real water sample using aptamer – reactant platform combination with activated Ag–Au alloy nanoparticles (NPs) by chemiluminescence (CL) method. CL is attributed to a catalytically enhanced decomposition of H2O2 by aptamer conjugated Ag–Au alloy NPs to produce reactive oxygen species. The Ag–Au alloy NPs were prepared by chemical method using double reducing agent (i.e. trisodium citrate and polyethylenimine) and used for detection of Co(II) from water by CL method. CL experiments were carried out with the variation of different parameters such as pH, concentration of luminol, concentration of H2O2 and Ag–Au alloy NPs. We found that Ag–Au alloy NPs have very good efficiency towards Co(II) detection. Analytical parameters and kinetics were studied in detail to know the nature and mechanism of CL in presence of aptamer conjugated Ag–Au alloy NPs. The linear range of the CL sensor of Co(II) is covered concentration from 0.01 to 10 µg/L with detection limit of 0.001 µg/L. The relative standard deviation for determination of Co(II) was 6.65 in 10 replicated measurements. CL method is first time applied to detect the Co(II) in real water samples at very low level using aptamer conjugated Ag–Au NPs as a catalyst.