Cathodic electrochemiluminescence of the peroxydisulphate–ciprofloxacin system and its analytical applications

Abstract

The cathodic electrochemiluminescence (ECL) of peroxydisulphate (S(2)O(8)(2-))-ciprofloxacin (CPF) system at a wax-impregnated graphite electrode was studied. When CPF was absent, S(2)O(8)(2-) was electrochemically reduced to sulphate free radical (SO(4)(•-)), and dissolved oxygen absorbed on the electrode surface was reduced to protonated superoxide anion radical (HO(2)(•)). The HO(2)(•) was oxidized by SO(4)(•-) to produce molecular oxygen in both singlet and triplet states. Some of the singlet molecular oxygen ((1)O(2)) further combined through collision to be an energy-rich precursor singlet molecular oxygen pair ((1)O(2))(2). A weak ECL was produced when (1)O(2) or ((1)O(2))(2) was converted to ground-state molecular oxygen ((3)O(2)). When CPF was present, a stronger ECL was produced, which originated from two emitting species. The main emitting species was excited state CPF (CPF*), which was produced by accepting energy from ((1)O(2))(2). The other emitting species was excited singlet molecular oxygen pair [((1)O(2))(2)*], which originated from the chemical oxidation of CPF by SO(4)(•-) and dissolved oxygen. Based on the stronger ECL phenomenon, an ECL method for the determination of either S(2)O(8)(2-) or CPF was proposed. The proposed ECL method has been applied to the determination of CPF in pharmaceutical preparations.

A sensitive dual-signal electrochemiluminescence immunosensor based on Ru(bpy)32+@HKUST-1 and Ce2Sn2O7 for detecting the heart failure biomarker NT-proBNP

“…The HO 2 À could be further oxidized to a singlet molecular oxygen pair ( 1 O 2 ) 2 or an excited singlet molecular oxygen pair [ 1 (O 2 ) 2 ]*, and both ( 1 O 2 ) 2 and [ 1 (O 2 ) 2 ]* can produce weak ECL when converting to ground-state molecular oxygen. 32 At such a low cathodic potential (À2.5 V in this work), although the selfluminescence of K 2 S 2 O 8 brings somewhat ECL background, its signal intensity is at least an order of magnitude lower than that of Ce 2 Sn 2 O 7 . 26 Thus, the self-luminescence of K 2 S 2 O 8 is negligible compared to the stronger ECL of Ce 2 Sn 2 O 7 .…”

Sonochemical synthesis of Ag nanoclusters: electrogenerated chemiluminescence determination of dopamine

“…To date, there are two main mechanisms in the ECL system, one is ion annihilation ECL, the other is coreactant ECL . For the Ag NC modified the ITO electrode in the absence of S 2 O 8 2– , it was found that the ECL signal was too weak to be distinguished from that of bare ITO electrode, which implied that S 2 O 8 2– plays a crucial role as coreactant in the process of Ag NC ECL.…”

An electrochemical immunosensor based on a nanostructured lanthanum oxide-substituted reduced graphene oxide interface for ultralow ciprofloxacin detection in milk samples

“…Many analytical techniques are being employed to determine CPX in different matrices, which include electrochemical, 9,10 immunoassay, 11 spectrofluorimetric, 12 capillary electrophoresis, 13 chemiluminescence, 14 spectrophotometry, 15,16 high-performance liquid chromatography 17 and liquid chromatography-mass spectroscopy 18 techniques. However, these analysis methods require expensive instrumentation, complex sample pretreatment, and preparation, which cannot meet large-scale actual testing.…”