Electrocatalytic Palladium Nanoclusters as Versatile Indicators of Bioassays: Rapid Electroanalytical Detection of SARS-CoV-2 by Reverse Transcription Loop-Mediated Isothermal Amplification.

Quantitative polymerase chain reaction (qPCR) is considered the gold standard for pathogen detection. However, improvement is still required, especially regarding the possibilities of decentralization. Apart from other reasons, infectious diseases demand on-site analysis to avoid pathogen spreading and increase treatment efficacy. In this paper, the detection of SARS-CoV-2 is carried out by reverse transcription loop-mediated isothermal amplification, which has the advantage of requiring simple equipment, easily adaptable to decentralized analysis. It is proposed, for the first time, the use of palladium nanoclusters (PdNCs) as indicators of the amplification reaction at end point. The pH of the medium decreases during the reaction and, in turn, a variation in the catalytic activity of PdNCs on the oxygen reduction reaction (ORR) can be electrochemically observed. For the detection, flexible and small-size screen-printed electrodes can be premodified with PdNCs, which together with the use of a simple and small electrochemical equipment would greatly facilitates their integration in field-deployable devices. This would allow a faster detection of SARS-CoV-2 as well as of other future microbial threats after an easy adaptation.

Arben Merkoҫi (Ed.): Paper based sensors

The following fourth and fifth chapters are devoted to paper-based electrochemical devices, including interesting and new points of view such as the role of paper in electroanalytical devices with special emphasis on its use as reactor as well as on the employ of different electrochemical techniques (amperometric, voltammetric, impedimetric or potentiometric), on the development of lateral and vertical flow paper-based microfluidic devices or on the detection in liquid and gas phases. The first chapter explores paper as a substrate for electrochemical micro-devices, being this principle of detection the most promising in the (bio)sensor field. The following three chapters (nineth, tenth and eleventh) are more specific, related to nanopaper-based (optical and electrical) sensors, nanoparticle-based lateral flow assays, and flexible cellulose-based devices for monitoring physical parameters. [Extracted from the article] Copyright of Analytical & Bioanalytical Chemistry is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)