Electrochemical Determination of Caffeine Using Bimetallic Au−Ag Nanoparticles Obtained from Low‐cost Green Synthesis

Abstract

A novel caffeine sensor was constructed. The sensor is based on a platinum electrode (PtE) modified with polypyrrole (PPY) and green synthesized AgÀ Au bimetallic nanoparticles. The work further describes the synthesis of silver nanoparticles (AgNPs), gold nanoparticles (AuNPs), as well as AgÀ Au bimetallic nanoparticles (BMNPs) using the extract of citrus sinensis (sweet orange) peels. The nanoparticles were used to form nanocomposite material supported on polypyrrole (PPY) and, consequently used to modify PtE using dropcast method. Synthesized nanomaterials were characterized by FT-IR, UV-Vis, XRD and TEM. Electrochemical characterization of the modified electrodes was conducted using the ferrocyanide/ferricyanide redox probe prepared in PBS. PPY/Ag-AuBMNP modified PtE exhibited faster electron transport properties as well as enhanced catalytic current response as compared to bare-PtE, PtE/AgNPs, PtE/AuNPs, PtE/Ag-AuBMNPs and PtE/PPY. By Square-wave voltammetry (SWV) the PPY/Ag-AuBMNPs modified PtE yielded a detection limit of 2.02 μM with a sensitivity of 0.75 μA/μM, in the caffeine concentration range of 0 μM to 59 μM. The proposed sensor further demonstrated good selectivity and was successfully applied for the detection of caffeine in commercial samples.

Recent Advances in Electrochemical Sensors for Caffeine Determination

“…In addition, the work of Masibi et al [ 104 ] demonstrated the preparation of a platinum electrode modified with bimetallic gold and silver nanoparticles and polypyrrole (PPY/AgAuBMNPs). The data obtained by electrochemical methods showed that the newly developed sensor was suitable for the detection of CF ( Table 7 ).…”

“…By comparing the results obtained in the papers published by Ferrag et al [ 97 ] and Masibi et al [ 104 ], it can be said that the electrode modification process should be another key parameter for selecting a suitable sensor. Both fabricated sensors, MWCNT-AuNP-CCE and PPY/AgAuBMNPs, show applicability in real samples ( Table 6 and Table 7 ) with low LOD values for CF, but Masibi and coworkers [ 104 ] chose a harmless modification process. In addition to obtaining good sensitivity, selectivity, and stability of the sensor, the authors should also work towards the use of environmentally friendly materials and substances in the modification processes.…”

Tween‐85 Surfactant‐Assisted Fabrication of Silver Monoliths for Catalytic Reduction of Methyl Orange and Caffeine Sensing

“…Additionally, a sol‐gel process was utilized to create a molecularly imprinted siloxane film on a glassy carbon electrode modified with multiwall carbon nanotubes/vinyltrimethoxysilane, which showed a linear response range of 0.75 to 40 μM L −1 and a detection limit of 0.22 μM L −1 for caffeine. An electrochemical biosensor for the detection of caffien was also developed, which exhibited excellent sensitivity and selectivity [37–47] …”

“…An electrochemical biosensor for the detection of caffien was also developed, which exhibited excellent sensitivity and selectivity. [37][38][39][40][41][42][43][44][45][46][47] Methyl orange is an azo dye that causes harmful effects on aquatic life and human beings. Azo dyes are large synthetic dyes class containing an azo group with an aromatic system that includes a chemical substituent that makes them soluble in water.…”

Hollow platinum-gold and palladium-gold nanoparticles: synthesis and characterization of composition-structure relationship

“…Bimetallic nanoparticles have received great attention in the last years, as they exhibit outstanding properties in comparison with the corresponding monometallic forms. These unique properties include the tuned frequency shift of plasmon modes [1][2][3], the high catalytic activity towards hydrogen generation [4], the carbon dioxide reduction [5], and the reduction and oxidation of various chemical compounds such as nitrophenol [6], caffeine [7], benzyl alcohol [8], and formic acid [9]. Bimetallic nanoparticles with different shapes and structures have been reported such as nanoframes [9], nanoprisms [10], core-shell [1,11], nanoflowers [12], and hollow nanoparticles [13,14].…”