Congratulations to PhD Candidate Daniel Kantanka Sarfo

Congratulations Daniel!

The MRS Group offers its congratulations to PhD Candidate Daniel Kantanka Sarfo for having two articles published in high impact scientific journals this month. Details of these publications can be found below.

Fabrication of nanostructured SERS substrates on conductive solid platforms for environmental application

Published in the journal

Critical Reviews in Environmental Science and Technology

Abstract

Due to its high analytical sensitivity and field deplorability, surface enhanced Raman spectroscopy (SERS) has emerged as an analytical tool for detecting environmental toxicants in different matrices. Progress has been made towards development of methods for depositing nanostructures onto solid platforms to design SERS substrates. The properties of the solid platforms used for SERS substrates fabrications such as electrical and heat conductivity, malleability and foldability, have significant influence on the design of the nanostructures and are critical for SERS technique. This review takes a look at recent advances in commonly employed conductive solid materials such as indium tin oxide, carbon fiber, silicon wafers, polyaniline fiber and carbon nanotubes as the supporting platforms for fabricating SERS substrates. It also examines their influence on the fabrication method, the morphology of the nanostructures formed as well as the hot spot density on the resultant novel SERS substrates. Real world applications of these substrates for the detection of environmental toxicants over the past decade have been shown. The review indicates that while significant advances have been made on the use of the conductive properties of these support platforms for SERS substrate fabrication, their subsequent application to detect environmental toxicants have not been fully explored.

Available from

https://www.tandfonline.com/eprint/48qEW2kB24S8tbRAPHjx/full?target=10.1080%2F10643389.2019.1576468&

Fabrication of dual function disposable substrates for spectroelectrochemical nanosensing

By Daniel K.Sarfo, Emad L.Izake, Anthony P.O’Mullane, Teng Wang, Hongxia Wang, Tuquabo Tesfamichael & Godwin A.Ayoko

Published in the journal

Sensors and Actuators B: Chemical

Abstract

In this work, we demonstrate the fabrication of disposable and field deployable nanostructured conductive substrates for dual detection by Surface Enhanced Raman Scattering (SERS) and electrochemistry. Using a one-step potentiostatic process, gold nanostructures were electrodeposited on three substrates: bare indium tin oxide (ITO) electrode, ITO coated with plane gold and carbon fibre (CF) covered with ZnO nanowires (ZnO NWs). Their sensitivities were enhanced by incorporating the plane gold layer and ZnO NWs. The intensity of SERS signals produced on the nanostructured ITO substrates with 0.1 μM quinolinethiol were of the order: nanostructured gold-coated ITO > nanostructured bare ITO. The higher SERS signal on the nanostructured gold-coated ITO was attributed to the coupling between the surface plasmon polariton provided by the gold under layer and the surface plasmon resonance of the Au nanostructures. The ZnO NWs on the carbon fibre provided additional surface area for electrodeposition of gold nanostructures at high density. This led to multiple hotspots formation yielding high SERS signal intensity relative to that on a nanostructured bare carbon fibre. The nanostructured substrates, demonstrated good SERS signal reproducibility with relative standard deviation of 5.19%, 3.28% and 4.53% for Au/ITO, Au/Au-ITO and Au/ZnO-CF respectively. To demonstrate the potential application of these substrates and estimate their sensitivities, they were used to detect melamine by SERS at 1 pM (for Au nanostructures on bare ITO), 1 fM (for Au nanostructured gold-coated ITO), and 0.1 nM (for Au nanostructures on ZnO NWs-coated CF) concentrations with LOD of 0.118 pM, 0.189 fM and 57.4 pM respectively. Taking advantage of the conductive properties of gold nanostructured ITOs, electrochemical detection of 0.1 μM melamine (with an LOD of 0.05 μM) was also demonstrated. Hence, these substrates are potentially useful for SERS and electrochemical-based detection of organic toxicants.

Available From

https://www.sciencedirect.com/science/article/pii/S092540051930214X?via%3Dihub