Highly Sensitive and Selective Amperometric Detection of Periodate at Glassy Carbon Electrode Modified with a Cyclometalated Iridium(III) Complex and Single‐Wall Carbon Nanotubes

Abstract

Single-wall carbon nanotubes (SWCNTs) were used as an immobilization matrix to incorporate [Ir(ppy) 2 (phen-dione)](PF 6 ) complex onto a glassy carbon electrode for the study of electrocatalytic reduction of periodate ion. Detailed preliminary electrochemical data for the Ir(III)-complex in acetonitrile solution and for the modified GCE/SWCNTs/[Ir(ppy) 2 (phen-dione)](PF 6 )/CGE are presented. The modified electrode was applied to selective amperometric detection of periodate through its electrocatalytic reduction to iodide at 0.200 V and pH 2.0. The use of amperometry resulted in two calibration plots over the concentration ranges of 1-20 µM and 20-450 µM, with a detection limit of 0.6 µM and sensitivity of 198 nA µM -1 .

A highly selective Cd‐based metal‐organic framework fluorescent probe for rapid recognition of cephalothin in water

“…The experimental findings demonstrated that within the 0–100 μM range, the fluorescence intensity of the 1 ‐H 2 O suspension exhibited an increase corresponding to the rise in CET concentration (Figure 4a). Based on the above, in order to quantitatively study the fluorescence enhancement efficiency, the fluorescence enhancement efficiency K EC is introduced, which is defined as ( I − I 0 )/( I 0 [A]) ([A] is the analyte concentration) 34 . As shown in Figure 4b,c, a strong linear correlation is observed between the ratio of fluorescence intensity ( I / I 0 ) and the concentrations of CET within the 0–50 μM range of CET, but with the increase in CET concentration after 50 μM, the linearity is not ideal.…”

“…Based on the above, in order to quantitatively study the fluorescence enhancement efficiency, the fluorescence enhancement efficiency K EC is introduced, which is defined as (I À I 0 )/(I 0 [A]) ([A] is the analyte concentration). 34 As shown in Figure 4b,c, a strong linear correlation is observed between the ratio of fluorescence intensity (I/I 0 ) and the concentrations of CET within the 0-50 μM range of CET, but with the increase in CET concentration after 50 μM, the linearity is not ideal. In the concentration interval from 0 to 50 μM, the I/I 0 and concentrations of CET conform to the linear equation I/I 0 = [CET] Â 5.4750 Â 10 4 M À1 + 0.98 (R 2 = 0.99803), with the K EC value of 5.4750 Â 10 4 M À1 and the limit of detection (LOD) determined to be 165 nM using the calculation formula 3σ/K EC (σ denotes the standard deviation of the measurement for the blank).…”

An Ir(III) complex chemosensor for the detection of thiols

“…[42] On the other hand, GSH, as the most abundant non-protein thiol, is a major reductant in internal cellular compartments. [15,43] As a consequence, we chose the structurally related 1,10-phenanthroline-5,6-dione (phendione) moiety as the N^N donor for the iridium(III) complex 1 ,[41] which also coordinates two C^N ligands (ppy). We anticipated that the reduction of the phendione N^N donor by GSH, generating complex 2 , may influence the MLCT state of the iridium(III) complex, thereby allowing 1 to act as a luminescent chemosensor for thiols (Figure 1).…”

“…[41] A suspension of [Ir(ppy) 2 ] 2 Cl 2 (ppy = 2-phenylpyridine) (0.2 mmol) and 1,10-phenanthroline-5,6-dione (phendione) (0.42 mmol) in a mixture of CH 2 Cl 2 :MeOH (1:1, 20 ml) was refluxed overnight under N 2 . The product mixture was then allowed to cool down to 25°C, and was filtered to remove unreacted dimer.…”

An ESIPT based fluorescent probe for highly selective and ratiometric detection of periodate

“…Several approaches for periodate detection were available, including electrochemical methods (Chatraei and Zare, 2013;Salimi et al, 2007;Shamsipur et al, 2013) and UV-vis spectrophotometry Benvidi et al, 2012;Ensafi and Chamjangali, 2003;Ni and Wang, 2007). To best of our knowledge, there is no efficient tool reported for discriminating periodate from other forms of iodine species and simultaneous monitoring of concentration changes of periodate with high accuracy.…”