Highly sensitive and selective detection of Bis-phenol A based on hydroxyapatite decorated reduced graphene oxide nanocomposites Mohammad K. Alam a,b , Mohammed M. Rahman c , Amir Elzwawy a , Sri Ramulu Torati a , Mohammad S. Islam d , Mitsugu Todo d , Abdullah M. Asiri c , Dojin Kim b , CheolGi Kim a, * a Department of Emerging Materials Science, DGIST, Daegu, 42988, Republic of Korea b Department of Materials Science and Engineering, Chungnam National University, Daejeon, 34134, Republic of Korea c Center of Excellence for Advanced Material Research (CEAMR) and Chemistry department, Faculty of Science, King Abdulaziz University, Jeddah 21589, P.O. Box 80203, Saudi Arabia d Research Institute for Applied Mechanics, Kyushu University, Kasuga, Fukuoka 816-8580, Japan A R T I C L E I N F O Article history: Received 21 February 2017 Received in revised form 24 April 2017 Accepted 26 April 2017 Available online 26 April 2017 Keywords: Reduced graphene oxide Hydroxyapatite Bis-Phenol A Biocompatibility Detection Limit A B S T R A C T A facile and cost effective chemical reduction method is employed for the preparation of reduced graphene oxide/hydroxyapatite (rGO/HAp) nanocomposites. The transmission electron microscopy images revealed that the HAp flakes are well decorated on the surface of rGO. The morphological structure of the as-synthesized rGO/HAp nanocomposites was confirmed through X-ray diffraction, Fourier transform infrared spectroscopy and Raman spectroscopy, while the composition and thermal stability were analyzed by energy dispersive spectra and thermogravimetric analysis, respectively. Furthermore, the effect of rGO/HAp nanocomposites for the proliferation of Human Mesenchymal Stem Cell (hMSC) was performed to confirm the biocompatibility. A selective chemical sensor based on rGO/ HAp modified glassy carbon electrode (GCE) for sensitive detection of Bis-phenol A (BPA) has been developed. Several important parameters controlling the performance of the BPA chemi-sensor were investigated and optimized at room conditions. The rGO/HAp/Nafion/GCE sensor offers a fast response and highly sensitive BPA detection. Under the optimal conditions, a linear range from 0.2 nmol L 1 to 2.0 mmol L 1 for the detection of BPA was observed with the detection limit of 60.0 pmol L 1 (signal-to- noise ratio, at an SNR of 3) and sensitivity of 18.98  10 4 mA.L/mmol.m 2 . Meanwhile, the fabricated chemi-sensor showed an excellent, specific and selective recognition to target BPA molecules among coexistence of other analytes in the buffer system. This novel effort initiated a well-organized way of efficient rGO/HAp/Nafion/GCE sensor development and practically analyzed the real hazardous environmental pollutants at room conditions. © 2017 Elsevier Ltd. All rights reserved. 1. Introduction The toxic Bis-phenol A (2,2-bis(4-hydroxyphenyl)propane, BPA) is an organic compound that broadly used in plastic industry as a monomer for producing epoxy-resins, polycarbonate, and other necessary polymer materials [1–3]. In daily life, BPA is omnipresent since it can be unintentionally released and migrated to the environment, food and drinking water due to waste water discharge from the plastic-manufacturing industry and from a broad assortment of food contact materials mainly resulting from polycarbonates as well as epoxy resins, such as infant feeding bottles, tableware, storage containers, and food can linings [4–6], and thus, humans may regularly consume trace amounts of BPA. Extensive research studies have shown that BPA is an environ- mental endocrine disrupting chemical, which can mimic and interfere with hormonal activities by disrupting growth, develop- ment, reproduction and reduction in immune function of humans [7,8], and also it can initiate probable cause for various types of cancer [9], even at very low concentration. To protect the noxious effect and the potential health risk of BPA, the development of sensitive and specific method with reliable, rapid and real-time analysis of trace level amount of BPA is highly significant and desired for the safety of human life. * Corresponding author. E-mail address: cgkim@dgist.ac.kr (C. Kim). http://dx.doi.org/10.1016/j.electacta.2017.04.135 0013-4686/© 2017 Elsevier Ltd. All rights reserved. Electrochimica Acta 241 (2017) 353–361 Contents lists available at ScienceDirect Electrochimica Acta journa l home page : www.e lsevier.com/loca te/ele cta cta