Fluorometric Determination of Zinc, Cadmium and Gallium Ions with a Fiber-Optic Sensor Having a Pyridoxal Isomer-Modified Chitosan/ Agarose Gel as a Sensing Probe

Abstract

A bifurcated fiber-optic sensor for Zn2+, Cd2+ and Ga3+ ions was fabricated. Chitosan modified with 5-formyl-3-hydroxy-4-hydroxymethyl-2-methylpyridine was immobilized on an agarose gel and used as a fluorogenic probe. The reproducibility of the response to Zn2+ was within 5% in eight successive measurements at 5.0X10-5 M (1 M=1 mol dm-3). A linear relationship with a correlation coefficient of 0.994 was obtained in the Zn2+ concentration range of 0 -2.0X105 M, and the detection limit was 1.0X106 M (S/ N=3). Cd2+ and Ga3+ ions were also detected, though with sensitivities somewhat lower than that for Zn2+. KeywordsFiber-optic sensor, modified chitosan, zinc ion, fluorometric determination, Schiff base formationChitosan, an aminopolysaccharide, has a high metalchelating ability.l This ability is enhanced by a chemical modification of the amino group. For example, the Cu2+ adsorption capacity of a Schiff-base derivative with salicylaldehyde is 5-times higher than that of chitosan itself.2 On the other hand, metal complexes of many aromatic Schiff bases are known to emit fluorescence. Determinations of Zn2+,3 A13+,4,5 Mgt+,6 Ga3+,' and Be2+ s using this phenomenon have been investigated, and some of these metal ions have been determined in practical samples such as blood plasma6, alloys7'8 and human urine' with high sensitivities and selectivities. These prompted us to employ an aromatic Schiff-base derivative of chitosan in fluorometric analyses of these metal ions.Recently, many types of fiber-optic sensors for metal ions have been developed: for example, A13+ has been determined by the use of morin immobilized on a biomembrane from mutton muscle9 or on a cellulose powder10 as a fluorogenic reagent. The advantages of fiber-optic sensors include a feasible avoidance of electrical interference and ready miniaturization.In the present paper, we report on a fiber-optic fluorosensor having a Schiff-base polymer derived from chitosan and a pyridoxal (4-formyl-3-hydroxy-5-hydroxymethyl-2-methylpyridine) isomer, 5-formyl-3-hydroxy-4-hydroxymethyl-

Versatile Applications Of Biopolymer Nanocomposites: A review

“…These optical sensing methods also have their own merits and demerits with distinguishing detection limits, sensing capacity, selectivity, and sensitivity. Considering the sensing capacity and for improvement of sensors selectivity, different researches have been conducted by using numerous fabricated materials including quantum dots, graphene oxideand biopolymers [73–81] . Last few decades’ scientists have preferred biopolymer materials including chitosan, cellulose, and nanocrystalline cellulose due to their exclusive properties and their natural unique characteristics such as eco‐friendly, low cost and nontoxic behavior, hence, studies proceed on the usefulness of biopolymers as optical sensors Over for sensing the contaminants including heavy metal ions.…”

“…Considering the sensing capacity and for improvement of sensors selectivity, different researches have been conducted by using numerous fabricated materials including quantum dots, graphene oxideand biopolymers. [73][74][75][76][77][78][79][80][81] Last few decades' scientists have preferred biopolymer materials including chitosan, cellulose, and nanocrystalline cellulose due to their exclusive properties and their natural unique characteristics such as eco-friendly, low cost and nontoxic behavior, hence, studies proceed on the usefulness of biopolymers as optical sensors Over for sensing the contaminants including heavy metal ions. Some of the recent constructed biopolymer sensor for the sensing of metal ions has been tabulated in Table 3.…”

Review—New Approaches for the Detection of Lithium Carbonate: The First Line Treatment for Bipolar Disorder

“…In addition, interferences measurements were done in the presence of other ions, the sensor showed a response only for lead and mercury and no response for zinc and cadmium. 56 Polymer based sensors.-These polymers are created for the detection of a wide range of targets like inorganic and organic molecules, proteins, and pharmaceuticals.…”

Optical Chemical Sensor for Screening Cadmium (II) in Natural Waters

“…Sanchez-Pedren et al, three kinetic methods based on flow injection, flow, and stopped-flow injection was applied for the determination of Cd(II) using an optode membrane that incorporates 1-(2-Pyridylazo)-2-Naphtol (PAN) in a plasticized poly (vinyl) chloride. Czolk et al have developed optic-chemical sensor (optode) for the detection of heavy metal ions using 5,10,15,20-tetra(p-sulfonatophenyl) porphyrin covalently immobilized onto a polymeric matrix, complexation of ions, such as Cd(II), Pb(II) or Hg(II) [18]. An optical-fiber chemical sensor (optode) have developed for determination of Zn(II) and Cd(II) mixtures using 2-(5-bromo-2-pyridylazo)-5-(diethylamino)phenol immobilized onto XAD-4 (Br-PADAP/XAD-4) by Kuswandi B et al [19].…”