Handheld, low-cost electronic device for rapid, real-time fluorescence-based detection of Hg2+, using aptamer-templated ZnO quantum dots

Daniel, SCG Kiruba and Kumar, Archiev and Sivasakthi, K and Thakur, Chetan Singh (2019) Handheld, low-cost electronic device for rapid, real-time fluorescence-based detection of Hg2+, using aptamer-templated ZnO quantum dots. In: SENSORS AND ACTUATORS B-CHEMICAL, 290 . pp. 73-78.

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Abstract

Mercury is one of the most acute toxic heavy metals at trace levels and its detection at parts per billion (ppb) scale in a low-cost, simple way remains challenging. Here, we report a novel ``Turn-On'' fluorescence sensor based on aptamer-templated ZnO quantum dots (QDs), which was further developed into an electronic detection device and utilized for the rapid detection of mercury ions (Hg2+). Binding of Hg2+ with the aptamer leads to the formation of a duplex, T-Hg2+-T, and this acts as a template for the formation of ZnO QDs. With an increase in the concentration of Hg2+, we observed an increase in duplex formation, leading to enhancement in the fluorescence. The limit of detection of the device is 0.1 ppb (0.5 nM), and experimental analysis has a linear range of detection between 0.1 and 10,000 ppb. Electron microscopy studies ascertained the crystalline nature of the aptamer-templated ZnO QDs in the presence of Hg2+. Finally, the sensing was implemented as a simple working electronic detection device prototype. A photodiode coupled with an LED source was connected to an Arduino Nanoboard for the development of the device. To the best of our knowledge, this is the first study to report an enhancement in the fluorescence of the aptamer-templated ZnO QDs with an increase in the concentration of Hg2+. Moreover, this is the first report of an analyte addition during the synthesis of QDs, leading to fluorescence-based sensing of the added analyte. Thus, a novel fluorescence sensor based on aptamer-templated ZnO QDs has been demonstrated with high sensitivity and selectivity, resulting in a simple electronic detection device.

Item Type:	Journal Article
Publication:	SENSORS AND ACTUATORS B-CHEMICAL
Publisher:	ELSEVIER SCIENCE SA
Additional Information:	Copy for this article belongs to ELSEVIER SCIENCE SA
Keywords:	Mercury; Aptamer; ZnO; Quantum dot; Device
Department/Centre:	Division of Electrical Sciences > Electronic Systems Engineering (Formerly Centre for Electronic Design & Technology)
Date Deposited:	24 May 2019 10:20
Last Modified:	24 May 2019 10:20
URI:	http://eprints.iisc.ac.in/id/eprint/62708

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