Chemiluminescence of Electrochemically Oxidized 9‐(Phenylthiophosphoryloxymethylidene)‐10‐methylacridan Derivatives

Abstract

The electrochemistry and electrochemiluminescence (ECL) properties of acridan phosphate ester are reported. Electrochemical oxidation of 9-(phenylthiophosphoryloxymethylidene)-10-methylacridan disodium salt (Compound 1) yields the corresponding acridinium ester. The latter undergoes a fast reaction with hydrogen peroxide forming an intermediate, which produces electronically excited 9-methyl acridone and emits blue light after relaxation to the ground state. The electrochemical oxidation of this compound appears to occur in two one-electron steps and light emission is observed for both steps. The chemiluminescence reaction could also be triggered by electrochemical oxidation of Compound 1 in the absence of H 2 O 2 when the solution was saturated with O 2 . Mechanisms for these reactions based on ECL, voltammetry and in situ UV-vis identification of the oxidation products are proposed. Due to the low electrode potential required to achieve ECL emission and the occurrence of light emission in the absence of hydrogen peroxide, this compound is proposed as a label for rapid and sensitive determination of biomolecules in automated analysis.

Aqueous Electrogenerated Chemiluminescence of Self-Assembled Double-Walled Tubular J-Aggregates of Amphiphilic Cyanine Dyes

“…This background signal is greatly decreased by purging the supporting electrolyte solution with argon before placing it in the spectroelectrochemical cell and was not observed in the absence of J-aggregates (Supporting Information). Since the background signal decreases upon purging with argon, the background is attributed to reactive oxygen (RO) species in solution due to the aqueous alkaline conditions. ,, However, since the concentration of O 2 is less than 1.3 mM and the signal contribution is at most ∼8%, these RO species do not influence the overall efficiency and reaction mechanism of our system and thus are not included in the proposed mechanisms.…”

“…Since the background signal decreases upon purging with argon, the background is attributed to reactive oxygen (RO) species in solution due to the aqueous alkaline conditions. 5,53,56 However, since the concentration of O 2 is less than 1.3 mM 57 and the signal contribution is at most ∼8%, these RO species do not influence the overall efficiency and reaction mechanism of our system and thus are not included in the proposed mechanisms. Although the low potential at which ECL occurs suggests the emission is from C8S3 J-aggregates rather than C8S3 monomers, more definitive evidence can be obtained from a spectrum of the ECL emission.…”

Electrogenerated Chemiluminescence and Its Biorelated Applications

“…As in the case of luminol (section 3.3), blue intense ECL emission was reported to be produced in alkaline solutions after electrochemical oxidation of an acridan phosphate ester [9-(phenylthiophosphoryloxymethylidene)-10-methylacridan disodium salt] in the presence of H 2 O 2 or dissolved molecular oxygen . This compound could be employed as a label in aerated sample solution for automated biomolecule analysis without the addition of H 2 O 2 .…”

Electrochemiluminescence of Acridines

“…In particular, 9‐(phenylthiophosphoryloxymethylidene)‐10‐methylacridan disodium salt is stable in the presence of hydrogen peroxide in strong alkaline pH for at least 40 min. Moreover, ECL of 9‐(phenylthiophosphoryloxymethylidene)‐10‐methylacridan disodium salt emission is observed in the absence of hydrogen peroxide at a low electrode potential of 0.26 V, making it an attractive label for rapid and sensitive determination of biomolecules in automated analysis .…”

“…An alternatives trategy to avoid the unfavourable conversion of the acridinium ester to its inactivep seudobase is to employ some acridines that are relatively stable in alkalines olutions and in the presence of hydrogen peroxide,s uch as 2',6'-difluorophenyl 10-methylacridan-9-carboxylate ( Figure 1c) and 9-(phenylthiophosphoryloxymethylidene)-10-methylacridan disodium salt ( Figure 1d). These acridines are then converted to corresponding acridinium esters by electrooxidation to emit strong ECL ( Figure 10) [47].I np articular, 9-(phenylthiophosphoryloxymethylidene)-10-methylacridan disodium salt is stable in the presence of hydrogen peroxide in strong alkaline pH for at least 40 min.M oreover,E CL of 9-(phenylthiophosphoryloxymethylidene)-10-methylacridan disodium salt emission is observed in the absence of hydrogenp eroxide at al ow electrode potential of 0.26 V, makingi ta n attractive label for rapid and sensitive determination of biomolecules in automated analysis [48].…”