Succinyl-κ-carrageenan Silver Nanotriangles Composite for Ammonium Localized Surface Plasmon Resonance Sensor

Abstract

This research investigates the physicochemical properties of biopolymer succinyl-κ-carrageenan as a potential sensing material for NH4+ Localized Surface Plasmon Resonance (LSPR) sensor. Succinyl-κ-carrageenan was synthesised by reacting κ-carrageenan with succinic anhydride. FESEM analysis shows succinyl-κ-carrageenan has an even and featureless topology compared to its pristine form. Succinyl-κ-carrageenan was composited with silver nanoparticles (AgNP) as LSPR sensing material. AFM analysis shows that AgNP-Succinyl-κ-carrageenan was rougher than AgNP-Succinyl-κ-carrageenan, indicating an increase in density of electronegative atom from oxygen compared to pristine κ-carrageenan. The sensitivity of AgNP-Succinyl-κ-carrageenan LSPR is higher than AgNP-κ-carrageenan LSPR. The reported LOD and LOQ of AgNP-Succinyl-κ-carrageenan LSPR are 0.5964 and 2.7192 ppm, respectively. Thus, AgNP-Succinyl-κ-carrageenan LSPR has a higher performance than AgNP-κ-carrageenan LSPR, broader detection range than the conventional method and high selectivity toward NH4+. Interaction mechanism studies show the adsorption of NH4+ on κ-carrageenan and succinyl-κ-carrageenan were through multilayer and chemisorption process that follows Freundlich and pseudo-second-order kinetic model.

Succinyl-carrageenan on a localised surface plasmon resonance fiber sensor for ammonium ion assays

“…Furthermore, the indophenol reagent methods are complicated and dangerous because they contain hazardous phenol. 4,12 The performances obtained in the current work are comparable to other techniques such as colorimetric, chromatography, and electrochemical techniques, and they comply with the NH 4 + detection range stated by most of the country's environmental organizations. 13–16 Even though this fabricated sensor's LOD is higher, and its detection range is smaller than the commercial NH 4 + sensor using an Ion Selective Electrode (ISE), 17,18 it still offers some advantages including the fact that it is not affected by the electrical charge, it achieves straight forward detection that does not require any complex probe and has a smaller sensor probe.…”

“…This is due to the succinyl-carrageenan film that has a stronger interaction with NH 4 + than carrageenan and provides a more electronegative oxygen atom site for the interaction with the NH 4 + . 3,4 Compared to the previous technique using the conventional glass substrate LSPR using a triangular nanoparticle, this LSPR fiber optic sensor had a lower LOD and LOQ. However, the range of detection of this sensor is smaller compared to the LSPR technique.…”

“…Moreover, the current fiber optic LSPR sensor also offers a higher repeatability. 4 This is due to the properties of AgNPs produced using this method, which offer a firm and stable AgNPs on the fiber probe with five times repeatability.…”

“…It was also reported by Abu Bakar et al , in 2022 that the surface morphology of carrageenan and succinyl-carrageenan showed an uneven and wavelike distribution. 4 Meanwhile, Fig. 3(e) and (f) portray the cross-section of AgNP-carrageenan and AgNP-succinyl-carrageenan fiber, respectively.…”

Chlorophyll Detection by Localized Surface Plasmon Resonance Using Functionalized Carbon Quantum Dots Triangle Ag Nanoparticles

“…Localized surface plasmon resonance (LSPR) is an optical spectroscopic method caused by interactions of incident light with the surface of metallic structures [ 9 ]. These interactions cause the electron density to oscillate at a resonance frequency that strongly depends on the composition and geometry of nanoparticles (NPs) and the environment refractive index [ 10 ].…”