A novel bioassay based gold nanoribbon biosensor to aid the preclinical evaluation of anticancer properties

Abstract

In this work, we report a microbial biosensor fabricated for the preclinical assay of anticancer compounds.Gold nanoribbons were used as a transducer for mounting the microbe. For the synthesis of these unique Au nanostructures, quercetin stabilized gold nanoparticles (Q-AuNPs) were synthesized as a first step using onion peel. Later, dityrosine peptide was used as a sacrificial template for the synthesis of the gold nanoribbons (AuNRs). The structural morphology of the as-synthesized Au nanomaterial was examined using UV spectroscopy, XRD, SEM and TEM. The AuNRs were found to be <10 nm in diameter, which provided a good biocompatible environment and effective protection for the immobilization of Agrobacterium tumefaciens (At), a causative agent of crown gall disease. At is reported to cause tumors in plants through a tumorigenic mechanism similar to that of humans. Inhibition of At indicates that the inhibitory compound being screened exhibits anticancer activity. Clitoria ternatea (Ct) is traditionally used to cure many diseases and is known to possess anticancer activity. Therefore, we have used a Ct flower extract in the preclinical study of its anticancer activity against At by fabricating a simple electrochemical sensor. We have employed electrochemical techniques such as CV and EIS for the characterization of the developed microbial biosensor. Moreover, the as-synthesized AuNRs behave as an ideal transducer and platform, thus improving the electrode surface area and providing good biocompatibility for the immobilization of At. In contrast to other immobilization techniques and biosensors that often require elaborate procedures, cross-linking agents and rigorous chemical reactions, At was directly adsorbed onto the electrode under optimum conditions without any mediators. The results show that the developed biosensor is useful in the pre-clinical analysis of anticancer properties. Indeed the study examines the use of electrochemistry, demonstrating the rapid response and high sensitivity of the proposed sensor in contrast to bioassay procedures. In conclusion, the experimental results indicate that the developed biosensor accentuates the excellent properties of the synthesized AuNRs, which promises to be a novel avenue in designing biosensors.

Impedimetric analysis of interaction between DNA and phytochemical constituents’ of Calotropis procera for pre-clinical evaluation

“…The plant material was collected, identified and stored in accordance with the help of taxonomical experts. The soxhlet assisted extraction of the phytochemical constituents is as reported in our previous work [18]. Soxhlet extractions were performed using 50 g of powdered plant to which 50 ml of water was added.…”

“…The preparation of the modified electrode is as our previously reported work [18]. An electrode was prepared by drilling a Teflon bar to 0.…”

“…). The physical characterization of the modified electrodes using SEM and EDAX has been described in our previous work [18].…”

“…Diferuloylmethane from Curcuma longa demonstrates anti-cancer effects for colon cancer, breast cancer [16], lung metastases, and brain tumor [17]. Calotropis procera known as Arka have many medicinal properties and we have compiled in [18]. Briefly, the various parts of plant is used in the treatment of diseases like leprosy, eczema, inflammation, cutaneous infections, syphilis, malarial and low hectic fevers, and as a botifacient, rheumatism, as an anti-inflammatory and antimicrobial, malaria etc., [19] It is a plant grown in tropical and subtropical regions.…”

“…This work suggests that impedimetric analysis can also be utilized to detect the drug screening. We have previously reported the electrochemical prescreening of anticancer activity of the Calotropis procera plant extract towards LN-18 and DNA modified electrode [18]. In this study, we have extracted the phytochemicals constituents of Calotropis procera by Microwave method and the conventional Soxhlet extraction method.…”