Some luminol imide derivatives with different substituent groups have been designed and synthesized. Their electrochemiluminescence properties have been measured with a view to developing new biosensors. The ECL response to hydrogen peroxide in the presence of these luminescent derivatives has been investigated taking into account crucial factors such as the applied potential value, injection volume of hydrogen peroxide, and the substituent groups in molecular structures. The experimental data demonstrated that the substituent groups in these imide derivatives can have a profound effect upon the ECL abilities of these studied compounds. The present research work affords new and useful exploration for the design and development of new soft matter for ECL biosensors with luminol functional groups.
In recent several decades, in the development of biomimetic optoelectronic nanosensors, luminol is considered as an efficient system in chemiluminescence (CL) and electrochemiluminescence (ECL) measurements for the detection of hydrogen peroxide [
Electrochemiluminescence (ECL) reaction of luminol in the presence of hydrogen peroxide.
In the previous work, we reported the design and synthesis of functional luminol derivatives with different substituted groups and investigated the interfacial assembly of these compounds with different methods [
As an extension work, we reported here the electrochemiluminescence properties of functional luminol derivative containing different substituted groups with a view to developing new biosensors. The ECL response to hydrogen peroxide in the presence of these luminescent derivatives has been investigated taking into account crucial factors such as the applied potential value, injection volume of hydrogen peroxide, and the substituent groups in molecular structures. The present results may give useful clues for the design and development of new ECL biosensors with luminol functional groups.
All materials, luminol, cholesteryl chloroformate, benzoyl chloride, 1-naphthoyl chloride, methyl 3,4,5-trihydroxybenzoate, 4-hydroxybenzenecarboxylic acid, and other used reagents were obtained commercially from Alfa Aesar Chemicals, TCI Shanghai Chemicals, Sinopharm Chemical Reagent Co., Ltd (China), and used without further purification. All used solvents were obtained from Beijing Chemicals and were distilled before use. Deionized water was used in all cases. 4-Alkyloxy-benzoic acid and 3,4,5-tris(alkyloxy)benzoic acid with different alkyl substituent chains were synthesized in our laboratory according to our previous report [
Molecular structures and abbreviations of present luminol derivatives with different substituent groups.
The ECL setup was described previously in our reports [
Stock solutions of luminol and present luminol derivatives were dispersed into PBS buffer (pH 8.0) under vigorous stirring prior to use to avoid any precipitation. The screen-printed sensor was immersed in a glass cuvette protected by black paper to avoid light and filled with a PBS buffer (pH 8.0) containing luminol or its derivatives. After the application of a cyclic voltammetry potential (between 450 mV and 850 mV versusprinted Ag/AgCl) and stabilization of the luminescent background signal, the ECL reaction was initiated by the injection of hydrogen peroxide solution in the buffer-filled cell. A steady-state light signal was reached after
It was reported previously that the screen-printed electrodes can be efficiently used in PBS buffer (pH 8.0). In addition, a cyclic voltammetry potential of −0.40 V
ECL intensity as a function of potential for T-C14-Lu. The measurements were performed in PBS buffer (pH 8.0) containing 50 uM of T-C14-Lu. The ECL reaction was initiated by sequential injection of 30 uL hydrogen peroxide solution in the working medium.
In addition, at a potential value of −0.80 V, the ECL detection with different concentrations of hydrogen peroxide detection was performed for Lu-P-Ben, as shown in Figure
Calibration curves for hydrogen peroxide detection. The measurements were performed in PBS buffer (pH 8.0) containing Lu-P-Ben at concentrations of 50 uM. The ECL reaction was initiated by sequential injections of hydrogen peroxide in the working medium at volumes of 10 uL (a), 20 uL (b), 30 uL (c), and 40 uL (d), respectively.
Moreover, ECL measurements of luminol derivatives with different substituted groups were compared, as shown in Figures
Calibration columns for ECL detection of hydrogen peroxide. The measurements were performed in PBS buffer (pH 8.0). The ECL reaction was initiated by sequential injection of 30 uL hydrogen peroxide in the working medium.
Calibration columns for ECL detection of hydrogen peroxide. The measurements were performed in PBS buffer (pH 8.0). The ECL reaction was initiated by sequential injection of 30 uL hydrogen peroxide in the working medium.
In our previous work, we reported the synthesis and characterization of some luminol derivatives containing aromatic/alkyl substituted groups [
Some luminol imide derivatives with different substituent groups have been designed and synthesized. Their electrochemiluminescence properties have been measured with a view to developing new biosensors. The ECL response to hydrogen peroxide in the presence of these luminescent derivatives has been investigated taking into account crucial factors such as the applied potential value, injection volume of hydrogen peroxide, and the substituent groups in molecular structures. The experimental data demonstrated that the substituent groups in these imide derivatives can have a profound effect upon the ECL abilities of these studied compounds. The present research work affords new and useful exploration for the design and development of new soft matter for ECL biosensors with luminol functional groups.
The authors declare that they have no direct financial relation with the commercial identities mentioned in this paper that might lead to a conflict of interests for any of them.
This work was financially supported by the National Natural Science Foundation of China (Grant nos. 20903078, 21207112), the Natural Science Foundation of Hebei Province (Grant nos. B2012203060, B2013203108), the China Postdoctoral Science Foundation (Grant nos. 2011M500540, 2012M510770, and 2013T60265), the Science Foundation for the Excellent Youth Scholars from Universities and Colleges of Hebei Province (Grant nos. Y2011113, YQ2013026), the Scientific Research Foundation for Returned Overseas Chinese Scholars of Hebei Province (Grant no. 2011052), and the Open Foundation of State Key Laboratory of Solid Lubrication (Grant no. 1002).