Sensitive Electrochemical Penicillin Sensor Based on Screen‐printed Carbon Electrode Modified with Dendrimer‐encapsulated Pt Nanoparticles

Abstract

Penicillin is a group of antibiotics classified specifically as β-lactam antibiotics due to the presence of a β-lactam ring in its molecular structure, and has been widely used since its discovery in 1928.1,2 The facile analysis of penicillin has thus been of importance in various fields of applications including medical science, medicine, pharmaceutical industry, food industry, and environmental monitoring.3-6 Several sensing strategies have been developed for the detection of penicillin; they can be categorized mainly into three general approaches. The first involves the use of pH-sensitive indicator dyes. This type of penicillin sensor is based on the enzymatic hydrolysis of penicillin to penicilloic acid, resulting in a pH change that is sensed optically by means of an acid-base indicator.3 The second approach utilizes pH glass electrodes. The principle in the operation of this penicillin sensor is that the pH glass electrode senses changes in the H + concentration resulting from the catalyzed hydrolysis of penicillin by penicillinase. 7 The final approach is based on the principle of the field effect in semiconductor structures. This type of penicillin sensor provides many advantages over the first two types, mostly due to its potential for miniaturization and integration and also due to its rapid response. However, the development of a sensitive penicillin sensor that allows the detection of small amounts of penicillin at low micromolar levels rapidly and inexpensively is critically needed in order to meet the practical needs in many fields of application such as pharmaceutical production, clinical analysis of antibiotic tablets, and food control. 5,8,9 In this context, we report an electrochemical penicillin sensor utilizing dendrimer-encapsulated Pt nanoparticles (Pt DENs) as electrocatalysts for the sensitive detection of penicillin. As illustrated in Scheme 1, the electrochemical penicillin sensor was prepared using a screen-printed carbon electrode (SPCE), on which both Pt DEN and penicillinase were immobilized. Upon the addition of penicillin, the immobilized penicillinase catalyzes the hydrolysis of penicillin to penicilloic acid, resulting in the production of H + ions which are electrochemically detected by means of the catalyzed electrochemical reduction of the generated H + ions on the Pt DEN-modified SPCE surface. Specifically, we synthesized Pt DENs containing an average of 147 atoms using amineterminated sixth-generation polyamidoamine dendrimers, which we denote as G6-NH 2 (Pt 147 ), and immobilized the Pt DENs with penicillinase enzymes onto SPCE surfaces. The resulting SPCE exhibited highly enhanced electrocatalytic activity for the electrochemical reduction of H + ions, leading to significantly increased cathodic current of H + . Especially, the Pt DEN-modified SPCE resulted in the electrochemical detection of penicillin as low as 0.1 μM, which allowed sensitive analysis of penicillin even in human blood serum.Figure 1(a) shows transmission electron microscopy (TEM) images of the as-synthe...

Graphene oxide hybrid with amine‐terminated poly(amidoamine) dendrimers encapsulating Pt nanoparticles for electrochemical oxygen reduction reaction

“…The absorbance monotonically decreasing toward the longer wavelength was attributed to the formation of Pt nanoparticles inside G6-NH 2 , which was in agreement with previous studies reporting the synthesis of Pt nanoparticles encapsulated inside dendrimers. 28,29 F I G U R E (a) Schematic representation of the synthesis of G6-NH 2 -Pt. Blue and red dots represent Cu 2+ and Pt, respectively.…”

Electrochemically induced deposition of hydroxyl‐terminated poly(amidoamine) dendrimers encapsulating Pt nanoparticles on indium tin oxide for enhanced electrochemiluminescence

“…Recently, we have reported the electrochemical surface modification of electrode materials including glassy carbon, carbon nanotube, and indium tin oxide (ITO) via electro‐oxidative coupling of amine‐terminated dendrimers 12–14 . The electrochemical modification of electrode surfaces with dendrimers has provided an effective and unique means for surface decoration of electrodes with catalytic nanoparticles because the dendrimers are capable of encapsulating various types of catalytic nanoparticles inside their internal cavity 15–19 . In order to further expand the scope of dendrimers for application in the electrochemical surface modification, our attention has been directed to hydroxyl‐terminated dendrimers as well.…”

Facile Preparation of Ionic Liquid‐coated Copper Nanowire‐modified Carbon Paste Electrode for Electrochemical Detection of Etilefrine Drug

“…Nevertheless, the oxidation of ET‐HCl at a traditional CPE and the bare glassy carbon electrode (GCE) suffers from overvoltage and slow kinetics rate . To mitigate this problem, surface modification of electrodes by polymers, nanoparticles, organic compounds, surfactants, carbon nanotube, functionalized graphene, Cu oxide NWs has been widely studied. In addition, copper nanowires (Cu NWs) have enormous significant research attention with the interesting applications in the fabrication of high‐performance catalysts, chemical sensors, nanoelectronics, and solar cells .…”