Glutaraldehyde sandwiched amino functionalized polymer based aptasensor for the determination and quantification of chloramphenicol

Abstract

In the present work, the crosslinking property of glutaraldehyde (GA) is exploited to construct a 1,5-diaminonaphthalene (1,5-DAN) modified aptamer based sensor for the determination and quantification of chloramphenicol (CAP). The sensor was fabricated by electro-polymerizing 1,5-DAN on the edge plane pyrolytic graphite (EPPG) followed by immobilization of CAP selective aptamer on the amino functionalized polymer modified EPPG surface using GA, which resulted in covalent linkage with the -NH 2 groups of the aptamer as well as those present on the polymerized electrode surface.Resulting GA sandwiched aptasensor leads to a tremendous improvement in the stability and sensitivity of the sensor in comparison to one fabricated without crosslinking. Characterization of the modification protocol was done using scanning electron microscopy (SEM), quartz crystal microbalance (QCM) analysis, and electrochemical impedance spectroscopy (EIS). Under optimized parameters, CAP was detected in a linear working range of 50-500 fM with the detection limit and sensitivity of 11 fM (n ¼ 3, R.S.D ¼ 0.15%) and 0.023 mA fM À1 respectively. The practical utility of the developed aptasensor has also been demonstrated by analysing CAP in complex matrix like urine, commercially available pharmaceutical samples and the Rosetta cells supernatant. The observed results suggests that the present electrochemical aptasensor is suitable for the detection of CAP in medicines, diagnosis of chloramphenicol resistant bacteria and virus, as well as for checking its adulteration in food and other dietary supplements.

Aptamer-based Biosensors for Antibiotic Detection: A Review

“…Mehta et al [147] identified and investigated the ssDNA aptamer sequence which was later used in numerous studies dealing with the aptasensing of chloramphenicol. The lowest LOD could be obtained by Chen et al [173], followed by Rosy et al [169] using amperometric aptasensors. The structure of quinolone is marked red.…”

“…The presented aptasensor of Yadav et al [166] was further developed by Rosy et al [169], exploiting the cross linking properties of glutaraldehyde (GA). For sensor fabrication, first 1,5diamoinonaphtalene was linked to the working electrode, consisting of edge plane pyrolytic graphite (EPPG), via electro-polymerization.…”

Aptamer-Based Biosensors for Antibiotic Detection: A Review

“…Like the other antibiotics, there are more reports of constructed electrochemical aptasensors for the detection of chloramphenicol [ 41 , 49 , 112 , 164 , 165 , 166 , 167 , 168 , 169 , 170 , 171 , 172 , 173 , 174 , 175 ] As shown in Table 9 , the lowest LOD could be obtained using the proposed electrochemical aptasensor based on Y-shaped DNA probes [ 174 ]. These probe-based metal ions encoded the nanoscale metal-organic frameworks (NMOF) as a substrate, and a circular strand-replacement DNA polymerization (CSRP) target triggered the amplification strategy.…”

Conformational Changes of Enzymes and Aptamers Immobilized on Electrodes

“…The articles on electrochemical aptasensors cited in Table correspond to reports in which conformational changes are defined (or assumed) to explain the way the devices work. There are other reports in which the conformation is just mentioned, but not defined in detail. ,,− It can be observed that gold, including its nanoparticles (AuNPs), constitutes the surface that has been mainly used to associate the selected aptamer containing a thiol group, either directly tethered (−SH) or, more commonly, through a spacer arm containing that same terminal group.…”