LAUSR

Abstract Herein, a straightforward method is proposed to synthesize gold nanoparticles (AuNPs) by using sucrose as reducing and capping agent in alkaline solution, under ultrasound irradiation and mild temperature conditions. By the implementation of a fully-automated flow-batch system, commanded by Arduino®, the generation of nanoparticles with tunable optical properties was possible, with localized surface plasmon resonance bands between 523 nm and 559 nm. The characterization of the obtained AuNPs was performed by UV–Vis and IR spectroscopy, transmission electron microscopy, dynamic light scattering and X-ray diffraction. The as-synthesized AuNPs, spherical in shape and with average size of 10 nm, were used for detection of ciprofloxacin based on the localized surface plasmon resonance band changes at 526 nm induced by the presence of this antibiotic. A solid phase extraction procedure, using C18 as sorbent material, was included for clean-up of samples and preconcentration of ciprofloxacin prior to analysis. The method was successfully applied to determine ciprofloxacin in the concentration range between 50 and 150 μg L−1 with regression coefficients >0.99. The limits of detection were 12 and 16 μg L−1 for detection of ciprofloxacin in surface water and honey samples, respectively. Recovery values were in the range of 89–110%, with relative standard deviation