Surface Plasmon Resonance Sensor to Detect n‐Hexane in Palm Kernel Oil Using Polypyrrole Nanoparticles Reduced Graphene Oxide Layer

Abstract

Palm kernel oil was extracted using n-hexane. Rotary evaporator and oven were used to remove n-hexane from the oil. Measurement of n-hexane in low concentration is significant and interest subject. In this study, the concentration of n-hexane was measured using the surface plasmon resonance technique. In order to improve the sensitivity of surface plasmon resonance sensor, the polypyrrole nanoparticles decorated reduced graphene oxide (sensing layer) was prepared using the electrodeposition technique on the surface of gold film. Different concentration of n-hexane in isooctane and the palm kernel oil before and after purification was tested using sensing layer. The sensor limit was about 1 ppm. The results were matched with the gas chromatography results. The thickness and roughness of sensing layer were increased after the interaction with n-hexane which was obtained from atomic force microscopy.

Physicochemical, nutritional, and sensory characteristics of Chenopodium album, ashwagandha, flaxseed, and Giloy fortified bun

“…Stretching vibrations of C=O was found at 1390.34 cm −1 and –C–O stretching vibrations and CH 3 symmetrical stretching vibration were also observed at peak 1747.48 and 2928.30 cm −1 , respectively (Salar & Kumar, 2016). The peak at 724.06 cm −1 represents the C–O stretching and =C‐H bending (Sadrolhosseini et al, 2021).…”

Synthesis of hydrophilic carbon nanotube sponge via post-growth thermal treatment

“…Defects in the extended sp 2 conjugated structure of CNTs sponges may be due to aliphatic dangling groups, giving rise to the three signals at 2960, 2920 and 2850 cm -1 . [34] In addition to revealing the presence of the above mentioned groups that are common in both samples, FT-IR analysis also clearly shows that the thermal annealing in air does lead to a controlled insertion of oxygenated groups at expenses of the graphitic structure. Specific bands in the IR spectrum are indeed much more intense in the thermally treated sample.…”

“…Moreover, both samples present signals typical of extensively aromatic samples, such as C-C arom stretching at 1590 cm −1 (visible as shoulder of 1625 cm −1 peak) [32], and different in-plane (1220 cm −1 ) and out-of-plane (1065, 1020 and 800 cm −1 ) modes of aromatic C-H species [33] arising from defects in the graphitic structure of CNTs. Defects in the extended sp 2 conjugated structure of CNTs sponges may be due to aliphatic dangling groups, giving rise to the three signals at 2960, 2920 and 2850 cm −1 [34]. In addition to revealing the presence of the above mentioned groups that are common in both samples, FT-IR analysis also clearly shows that the thermal annealing in air does lead to a controlled insertion of oxygenated groups at expenses of the graphitic structure.…”

“…[36] A further consequence of the thermal treatment, apart from the insertion of oxygenated groups onto the surface of the CNT sponges, is the increasing rupture of the conjugated sp 2 structure, promoting the growth of linear saturated hydrocarbons, justifying the consistent growth of C-H stretching in the 2960-2850 cm −1 range, C-H bending at 1465 and 1357 cm −1 and C-H wagging at 800 and 720 cm −1 . [34] For comparison purposes, commercial multi-wall CNTs (Sigma Aldrich) were also treated in air at 450 °C for 1 h. The corresponding FT-IR spectra of pristine and annealed samples are shown in Figure 4b. Overall, it is possible to observe the same spectral features already observed for the CNTs sponges (Figure 4a).…”

Sensing Methods for Hazardous Phenolic Compounds Based on Graphene and Conducting Polymers-Based Materials

“…Polypyrrole (PPy) was widely used as the sensing layer in the development of sensors thanks to its environmental stability, high electron affinity, and remarkable electronic properties [196]. When PPy is used to modify the GCE for the HS-voltammetric detection of Ph, a low LOD of 0.07 µM was obtained [197].…”