Activated Nickel Platform for Electrochemical Sensing of Phosphate

Abstract

We report here a highly selective enzymeless approach for the determination of phosphate (PO(4)(3-)) by flow injection analysis (FIA). In this system, the activation of barrel plated nickel electrode (Ni-BPE) in alkaline media to form a Ni(OH)(2)/NiO(OH) film was found to trigger the adsorption of phosphate at the electrode surface. Based on the suppressed current of the electrocatalytic oxidation of glucose at the activated Ni-BPE in 0.1 M NaOH solution caused by adsorption of phosphate, we develop an FIA detection scheme for the determination of phosphate. Under the optimized conditions of flow rate = 300 microL/min and detection potential = 0.55 V vs Ag/AgCl with 25 microM glucose in 0.1 M NaOH as carrier solution, the calibration curve showed a linear range up to 1 mM. Possible interferences from the coexisting ions were also investigated. The results demonstrated that sensor could be used for the determination of phosphate in the presence of nitrate, chloride, sulfate, acetate, oxalate, carbonate, and some anionic species of toxicological and environmental interest, such as chlorate, chromate, and arsenate ions. The electrode can be effectively regenerated without extra treatment under the hydrodynamic condition. For eight continuous injections of 40 microM PO(4)(3-), a relative standard deviation of 0.28% was obtained, indicating good reproducibility of the proposed method. The detection limit (S/N = 3) was calculated as 0.3 microM.

Highly sensitive and selective detection of phosphate using novel highly photoluminescent water-soluble Mn-doped ZnTe/ZnSe quantum dots

“…The corresponding regression coefficient was 0.9976. The detection limit (LOD) was as low as 0.2 mmol/L [23]. (LOD ¼3s/s s was the slope of the calibration curve.…”

Electrochemiluminescence Sensor for Phosphate Ions Based on Europium(III)‐Modulated CdSe Quantum Dots

“…Phosphate anions exist in many different forms containing phosphate ion (PO 4 3À ), hydrogen phosphate ion (HPO 4 2À ), or dihydrogen phosphate ion (H 2 PO 4 À ) .Wellknown, phosphate anions and their derivatives are not only noted for their important roles in signal transduction and energy storage in living systems but are also responsible for the eutrophication of waterways (from the over use of phosphate-containing fertilizers) [1]. Besides, some health problems, such as hyperparathyroidism, vitamin D deficiency, and fanconi syndrome, can be diagnosed by measuring phosphate anions concentrations in body fluids [2].…”

“…Besides, some health problems, such as hyperparathyroidism, vitamin D deficiency, and fanconi syndrome, can be diagnosed by measuring phosphate anions concentrations in body fluids [2]. Accordingly, considerable detection strategies for phosphate anions and their derivatives have been developed including chromatography, spectrophotometry [3,4], fluorometry [5][6][7], electrochemical analysis [8,9], and enzymatic biosensors [10]. However, the drawbacks of most of these techniques are that they often require time-consuming sample pretreatment procedures, sophisticated instrumentation, large sample volumes, or specialized skills.…”

Glassy carbon electrode modified with hybrid films containing inorganic molybdate anions trapped in organic matrices of chitosan and ionic liquid for the amperometric sensing of phosphate at neutral pH

“…Page 3 of 34 A c c e p t e d M a n u s c r i p t 3 Molecules containing phosphate group are of special interest because of their ubiquitous presence in life. The presence of inorganic phosphate derived from fertilizers, similarly to nitrates, leads to an excessive growth (eutrophication) of aquatic plants and algae that disrupts aquatic life cycles.…”

“…For diagnostic purposes, the concentration of phosphate ion in human saliva is a variable, ranging from 5 to 14 mM. It is in the range of 0.81 to1.45 mM PO 4 3-in adult human serum [3]. Various detection strategies for phosphate have been developed, which include phosphate ion selective electrodes, amperometry, chromatography, flurometry, colorimetry, spectroscopy and enzymatic biosensors [4][5][6][7][8][9][10][11][12][13][14][15][16][17].…”