Zero waste, single step methods of fabrication of reduced graphene oxide decorated with gold nanoparticles

The study reports a facile and eco-friendly approach for nanomaterial synthesis and enzyme immobilization. A corresponding glucose biosensor was fabricated by immobilizing the gold nanoparticles (AuNPs) and glucose oxidase (GOD) multilayer films onto the polypyrrole (PPy)/reduced graphene oxide (RGO) modified glassy carbon electrode (GCE) via the electrodeposition and self-assembly. PPy and graphene oxide were first coated on the surface of a bare GCE by the electrodeposition. Then, AuNPs and GOD were alternately immobilized onto PPy-RGO/GCE electrode using the electrodeposition of AuNPs and self-assembly of GOD to obtain AuNPs-GOD multilayer films. The resulting PPy-RGO-(AuNPs-GOD)n/GCE biosensors were used to characterize and assess their electrocatalytic activity toward glucose using cyclic voltammetry and amperometry. The response current increased with the increased number of AuNPs-GOD layers, and the biosensor based on four layers of AuNPs-GOD showed the best performance. The PPy-RGO-(AuNPs-GOD)4/GCE electrode can detect glucose in a linear range from 0.2 mM to 8 mM with a good sensitivity of 0.89 μA/mM, and a detection limit of 5.6 μM (S/N = 3). This study presents a promising eco-friendly biosensor platform with advantages of electrodeposition and self-assembly, and would be helpful for the future design of more complex electrochemical detection systems.

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Layer-by-layer thin film of reduced graphene oxide and gold nanoparticles as an effective sample plate in laser-induced desorption/ionization mass spectrometry

Analytica Chimica Acta ◽

10.1016/j.aca.2013.11.050 ◽

2014 ◽

Vol 809 ◽

pp. 97-103 ◽

Cited By ~ 23

Author(s):

Tsung-Rong Kuo ◽

Di-Yan Wang ◽

Yu-Chen Chiu ◽

Yun-Chieh Yeh ◽

Wei-Ting Chen ◽

...

Keyword(s):

Thin Film ◽

Mass Spectrometry ◽

Gold Nanoparticles ◽

Graphene Oxide ◽

Reduced Graphene Oxide ◽

Ionization Mass ◽

Layer By Layer ◽

Desorption Ionization ◽

Reduced Graphene ◽

Layer Thin Film

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Reduced Graphene Oxide/Gold Nanoparticles Modified Screen-Printed Electrode for the Determination of Palmitic Acid

Journal of Sensors ◽

10.1155/2021/6684770 ◽

2021 ◽

Vol 2021 ◽

pp. 1-14

Author(s):

Chin Boon Ching ◽

Jaafar Abdullah ◽

Nor Azah Yusof

Keyword(s):

Gold Nanoparticles ◽

Graphene Oxide ◽

Palmitic Acid ◽

Reduced Graphene Oxide ◽

Palm Oil ◽

Water Mixture ◽

Reduced Graphene ◽

Electrochemical Approach ◽

Screen Printed

Palm oil is one of the major oils and fats produced in the world today. The quality of palm oil is crucial to be investigated, and one of the quality indices is free fatty acid (FFA) content. Therefore, in this study, an electrochemical approach for the determination of FFA has been explored as an alternative to replace the conventional method (titration method). The electrochemical method was developed based on electrochemically reduced graphene oxide (rGO) coupled with gold nanoparticles (AuNPs) deposited onto a screen-printed carbon electrode (SPCE) via drop-casting technique. The voltammetric behaviour of 2-methyl-1,4-naphthoquinone (VK3) in the presence of palmitic acid at the modified electrode was investigated in an acetonitrile/water mixture containing lithium perchlorate (LiClO4). The electrochemical detection of palmitic acid was based on the voltammetric reduction of VK3 to form the corresponding hydroquinone which is proportional to the concentration of palmitic acid. Under optimum conditions, the developed method showed a good linear relationship towards palmitic acid in the concentration ranging from 0.192 mM to 0.833 mM with the detection limit of 0.015 mM. The exploration of the developed system is expected to achieve high sensitivity and excellent selectivity towards the determination of FFA content in palm oil.

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