Direct Intercalation of Bis-2,2′,2″,6-terpyridylcobalt(III) into Zirconium Phosphate Layers for Biosensing Applications

Abstract

The direct intercalation reaction of [Co(tpy)(2)](2+) with the highly hydrated θ phase of layered zirconium phosphate (θ-ZrP) resulted in the formation of the oxidized [Co(tpy)(2)](3+) ion within the ZrP material. The X-ray powder diffraction patterns showed that the interlayer distance increases from 10.3 Å in θ-ZrP to 14.9 Å in the dry [Co(tpy)(2)](3+)-intercalated ZrP {[Co(tpy)(2)](3+):ZrP} phase. The complex remains electroactive within the layers of ZrP. The formal potential of a carbon paste electrode (CPE) modified with [Co(tpy)(2)](3+):ZrP (E°' = 40.8 mV versus Ag/AgCl, 3.5 M NaCl) is non-pH-dependent. However, the sensitivity of the [Co(tpy)(2)](3+):ZrP-modified CPE for the detection of reduced nicotinamide adenine dinucleotide (NADH) electrooxidation was lower than that of a previously reported CPE modified with [Ru(phend)(2)bpy](2+)-intercalated ZrP. (1) To improve the characteristics of NADH electrooxidation of the [Co(tpy)(2)](3+):ZrP-modified CPE, we included the enzyme diaphorase in solution, which increased the electrocatalytic current for NADH oxidation. A bienzymatic lactate biosensor was constructed and used for lactate sensing.

Revisiting the Old and Golden Inorganic Material, Zirconium Phosphate: Synthesis, Intercalation, Surface Functionalization, and Metal Ion Uptake

“…Clearfield et al in 2012, reported direct intercalation of bis-2,2′,2″,6-terpyridyl-cobalt(III) [Co(tpy) 2 ] 3+ into θ-ZrP and investigated its biosensing applications for lactate ion. 168 The diffraction studies indicate an increase in gallery space (14.9 Å) upon increased loading of [Co(tpy) 2 ] 3+ . The [Co(tpy) 2 ] 3+ is…”

“…A similar Donnan membrane effect was also shown to operate in the aqueous phase removal of fluoride ions by a ZrP@MPS nanocomposite functionalized with quaternary ammonium groups. 168 In another study, Ma et al synthesized a novel polysulfone capsule encapsulated with α-ZrP by a phase inversion method in the presence of N-methyl-2-pyrrolidone (NMP) solvent. 259 The phase inversion method is a phase separation method and involves the removal of solvent from liquid-polymer solution leaving behind a porous solid material.…”

A Cationic Ru(II) Complex Intercalated into Zirconium Phosphate Layers Catalyzes Selective Hydrogenation via Heterolytic Hydrogen Activation

“…Notably, the present intercalation of a cationic metal complex into ex-ZrP layers cost less time (6 h) as compared with that reported in previous references (usually several days). [56,57] The possible reasons for the difficulty in direct intercalation of metal complexes into α-ZrP were relatively higher van der Waals forces between the layers and the diffusion-limiting process of intercalating agents to migrate toward the center of the gallery. [58] The phase structure of the pristine α-ZrP, ex-ZrP, and the corresponding Ru-ZrP catalysts were determined by XRD patterns (Figure 1).…”

New Applications of Zirconium Phosphate Nanomaterials

“…21 The direct intercalation of [Ru(bpy) 3 ] 2+ was followed by intercalation studies of Re, Co, Fe, and Pt compounds, for possible applications in photochemistry, amperometric biosensors, and vapochromism. [22][23][24]28 More recently, our group has been involved in studying new applications of ZrP for anticancer drug delivery and electrocatalysis for the oxygen evolution reaction (OER).…”

“…For the next 50 years, new developments included the study of the ion-exchange and intercalation chemistry of these materials, − , new nanophases and hybrid materials, layer exfoliation, surface modification, and the application of these materials in catalysis, fuel cells, photophysics and photochemistry, electron-transfer reactions and amperometric biosensors, − vapochromic materials, protein adsorption and intercalation, , and lubricant additives …”