Coupling O₂ and K₂S₂O₈ Dual Co‐reactant with Fe‐N‐C Modified Electrode for Ultrasensitive Electrochemiluminescence Signal Amplification

Abstract

The sensitivity of electrochemiluminescence (ECL) sensor relies on the co-reactant and the electrode modification materials. Herein, dual co-reactants (O 2 and K 2 S 2 O 8 ) and porous carbon with doped N and Fe 3 O 4 (Fe-NÀ C) materials modified electrode were proposed for ECL signal amplification in a quantum dots (QDs) ECL system. Firstly, Fe-NÀ C materials were synthesized and the effect of pyrolysis temperature on Fe-NÀ C materials was evaluated towards ECL intensity. The developed ECL sensor exhibited high sensitivity and specificity towards oxytetracycline (OTC) detection with a detection limit of 0.27 pM ( � 0.12 ng L À 1 ). Doped N in porous Fe-NÀ C materials not only promoted the O 2 reduction reaction (ORR) but also accelerated the conversion of Fe 2 + /Fe 3 + in Fe 3 O 4 , which catalyzed coreactants to their relevant free radicals (SO 4 ⋅À and ⋅OH). Moreover, the decomposition efficiency of K 2 S 2 O 8 and generation of free radical were promoted through the reaction between OH⋅ and K 2 S 2 O 8 , as well as SO 4 ⋅À and H 2 O. Therefore, the amounts of excited QDs were increased via the energy and electron transfer process between QDs and free radicals, resulting in a highly enhanced ECL signal. The proposed signal amplification strategy offered an efficient way to improve the catalytic activity of ECL reagents and to boost the sensitivity of ECL sensors.[a] X.

Enhanced Electrochemiluminescence Detection for Hydrogen Peroxide Using Peroxidase-Mimetic Fe/N-Doped Porous Carbon

“…nanocomposites.-The experimental processes can refer to our previous work. 32 Firstly, FeCl 3 •6H 2 O (0.15 mM, 0.4054 g) and NH 2 -BDC (0.075 mM,0.1359 g) were sequentially added to DMF (32.3 mL) with an interval of 30 min and stirred until FeCl 3 •6H 2 O and NH 2 -BDC were dissolved. Secondly, the mixture was heated in an oven at 110°C for 24 h and the obtained turbid liquid was centrifuged at 6000 rpm for 10 min.…”

“…The selection of specific pyrolysis temperature was based on our previous work. 32 The obtained product was Fe/N-C nanocomposite which was cooled naturally and ground into a uniform powder.…”

Unmasking the Electrochemiluminescence Properties of Ternary Mn/Fe/Co Metals Doped Porous g-C3N4 Fiber-like Nanostructure

“…Mn, Fe, and Co dopants can be used to tune the emission properties of ECL luminophores, allowing for the design of ECL systems with tailored emission spectra. These metal dopants can be used as catalysts in the oxidation and reduction of various compounds, including potassium persulfate (K 2 S 2 O 8 ). − In the reduction of K 2 S 2 O 8 , Mn, Fe, and Co ions act as electron donors, undergoing oxidation to higher oxidation states. For example, in the presence of Mn ions, K 2 S 2 O 8 can be reduced to SO 4 2– ions, where the Mn 2+ ions act as catalysts.…”

Multiple signal amplification strategy using porous materials and novel controlled release self-on mode for ultrasensitive immunoassay

“…•− radicals, 18 improving the ECL intensity and efficiency. Further, Fe-MOF was introduced as a catalyst to stimulate the production of more SO ), 19 and its unique properties of well-defined porosity, good conductivity, high surface area and active sites endow Fe-MOF with ideal potential as a catalyst. 20 Therefore, the use of Fe-MOF can increase the performance of the constructed ECL sensor.…”

“…Further, Fe–MOF was introduced as a catalyst to stimulate the production of more SO 4 ˙ − radicals. The valence transformation between Fe( ii / iii ) is remarkably effective in K 2 S 2 O 8 activation compared with other metal catalysts (such as Co 2+ , Ni 2+ , Ce 3+ ), 19 and its unique properties of well-defined porosity, good conductivity, high surface area and active sites endow Fe–MOF with ideal potential as a catalyst. 20 Therefore, the use of Fe–MOF can increase the performance of the constructed ECL sensor.…”