colorimetric sensor array based on au nanoparticles for detection and discrimination of antibiotics in environmental water

Abstract: antibiotics (abs) have been regarded as powerful medications to treat or prevent bacterial infections. the antibiotic resistance though, is one of daunting challenges of our time which has been attributed to the overuse of these drugs and usage of antibiotic-contaminated food resources. developing rapid and visual detection methods capable of simultaneously monitoring abs is highly desired due to their harmful effects on human health. in the present study, we have designed a colorimetric sensor array consisting of two types of gold nanoparticles (i.e., citrate-capped gold nanoparticles (cit-aunps) and borohydride-capped gold nanoparticles (bh4-aunps) for the discrimination and determination of critical abs belong to different antibiotic classes (i.e., azithromycin (azt), amoxicillin (amox), ciprofloxacin (cip), clindamycin (cln), cefixime (cfx), doxycycline (dox) and metronidazole (met)). the design principle of the probe was based on the aggregation of cit-aunps and bh4-aunps in the presence of abs. unique aggregation profiles of sensor elements in the presence of the targets at various ph conditions, using citrate and phosphate buffers, were visually assessed and statistically analyzed by various data visualization and pattern recognition methods. namely, linear discriminant analysis (lda) and partial least squares (pls) regression were employed for the qualitative and quantitative determination of abs. the excellent statistical parameters for classification (sensitivity 100% and specificity 100%) and for multivariate calibration (r2cal>0.99 and r2cv>0.99 ) show the ability of the designed array to discriminate and detect abs. also, the color variation of the sensor array in presence of abs indicates rapidly visual discrimination of abs by the developed sensor array. finally, the practicality of the sensor array in real samples was investigated by the determination of abs in the river and underground water by which the potential of the probe for on-site determination of antibiotics was successfully verified.