Colorimetric determination of resorcinol based on localized surface plasmon resonance of silver nanoparticles

In this paper, we have developed a simple colorimetric method for detection of resorcinol (RE); the method is based on the reaction of RE with silver ions (oxidizing agent) in the presence of starch as a stabilizer and formation of silver nanoparticles (AgNPs). At nanometer dimensions the electron cloud can oscillate on the particle surfaces when dispersed in liquid media so these nanoparticles exhibit a strong UV-Vis extinction band. A UV-Vis spectrophotometer is used to monitor the changes of the localized surface plasmon resonance (LSPR) of AgNPs at a wavelength of 430 nm. There is a linear relationship between absorbance intensity of AgNPs and the concentration of RE over the range of 4 × 10(-6) to 1.1 × 10(-5) mol L(-1) at 430 nm. The detection limit was 1.2 × 10(-6) mol L(-1). The proposed method has been successfully applied for the determination of RE in anti-acne solution and spiked shampoo samples.