Vol.:(0123456789) 1 3 International Journal of Environmental Science and Technology https://doi.org/10.1007/s13762-018-1745-4 ORIGINAL PAPER Synthesis of 4‑formyl pyridinium propylthioacetate stabilized silver nanoparticles and their application in chemosensing of 6‑aminopenicillanic acid (APA) A. Anwar 1,2  · M. R. Shah 2  · S. P. Muhammad 3  · K. Ali 3  · N. A. Khan 1 Received: 20 September 2017 / Revised: 20 February 2018 / Accepted: 10 May 2018 © Islamic Azad University (IAU) 2018 Abstract Widespread use of antibiotics for humans and animals health has led to drugs entering the environment, such as lakes and streams worldwide. It is imperative to develop methods to screen these in drinking water supplies. We developed a novel nanoparticles-based probe to detect the β-lactam skeleton 6-APA. Cationic ligand thiopyridine stabilized silver nanoparti- cles (ThPy-AgNPs) were synthesized and used for chemosensing of the drug 6-aminopenicillanic acid (6-APA). Along with several drugs, during UV–visible titration with ThPy-AgNPs, a distinctive decrease in surface plasmon resonance bands absorbance was observed with 6-APA. The ThPy-AgNPs-based detection system for 6-APA is based on the phenomenon of de-aggregation and is monitored by using UV–visible spectrophotometry and atomic force microscopy measurements. The process is relatively rapid, highly specifc and selective for 6-APA when tested against several other drugs. This optical method can recognize 6-APA as low as 1 μM concentration, and drug detection is independent of the pH of media. Moreo- ver, the optimized sensing protocol is able to sense 6-APA in human blood plasma samples and is not altered by presence of other interfering drugs. It is anticipated that this method will be of immense value to detect 6-APA for blood samples and drinking water. Keywords Silver nanoparticles · Drug sensing · 6-APA · Human blood plasma Introduction 6-Aminopenicillanic acid (6-APA) forms the skeleton core of β-lactam antibiotics such as penicillin and other related compounds. Penicillins are commonly used as broad-spec- trum antibiotics against both Gram-positive and Gram-neg- ative organisms (Wishart 1984). Their limitations include low stability, and susceptibility to form degradation products (Tyczkowska et al. 1992). Formation of degradation prod- ucts may cause decrease in drug efcacy, as well as induc- ing some side efects. These antibacterial agents can cause inactivation of penicillin binding proteins (PBP), utilized in the production of bacterial cell wall formation through stable covalent acyl complexes. Hence, this irreversible substrate binding inhibits the cell wall manufacturing of PBP, result- ing in cell death (Matagne et al. 1998; Fisher et al. 2005). Moreover, the widespread use of penicillin antibiotics for humans and animals has led to an alarming situation in the environment, in particular due to causing toxic efects in aquatic organisms in lakes and streams all over the world Editorial responsibiility: Binbin Huang. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s13762-018-1745-4) contains supplementary material, which is available to authorized users. * A. Anwar ayazanwarkk@yahoo.com 1 Department of Biological Sciences, School of Science and Technology, Sunway University, 47500 Subang Jaya, Selangor, Malaysia 2 H.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan 3 Institute of Chemical Sciences, University of Peshawar, Peshawar 25120, Pakistan