Perylene diimide and g-C3N4 nanosheet as potential-resolved cathode luminophores for ultrasensitive ratiometric electrochemiluminescence immunosensor

• Published in: Sensors and actuators. B, Chemical Chemical, 2022-11, Vol.371, p.132492, Article 132492
• Main Authors: Zhang, Wei, Cui, Xiaomin, Li, Fenghua, Yan, Wei, Wang, Yunyun, Shang, Lei, Ma, Rongna, Jia, Liping, Li, Chuan, Wang, Huaisheng
• Format: Article
• Language: English
• Subjects: Absorption spectra; Antibodies; Antigens; Biosensors; Carbon nitride; Diimide; Dual-quenching mechanism; Electrochemiluminescence; Energy transfer; G-C3N4 nanosheet; Immunosensors; Nanosheets; Perylene diimide; Potassium persulfate; Potential-resolved cathode luminophores; Quenching; Ratiometric electrochemiluminescence immunosensors
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2022.132492

In electrochemiluminescence(ECL) field, the shortage of potential-resolved luminophores severiously limited the development of biosensors for accurate assay such as ratiometric biosensors. In this work, N,N′-dimethyl-3,4,9,10-perylenedicarboximide(PDI-CH3) and graphite-like carbon nitride(g-C3N4) nanosheet was firstly reported to produce potential-resolved ECL with coreactant K2S2O8 between 0 and − 1.2 V. And there was good overlap between the ECL spectrum of g-C3N4 and the absorption spectra of PDI-CH3. Moreover, PDI-CH3 and g-C3N4 were used to construct ECL ratiometric system for sandwiched immunosensors to detect tumor marker carcinoembryonic antigen (CEA), in which g-C3N4 was used as ECL platform and PDI-CH3 was used as ECL label of secondary antibody(Ab2). Increasing the CEA concentration, the loading of PDI-CH3 on the electrode stepwisely increased, which leaded to gradual increase of ECLPDI-CH3 at − 0.5 V and significant decrease of ECLg-C3N4 at − 1.2 V due to the high quenching effects of PDI-CH3 to g-C3N4 through dual-quenching mechanism: competitive consumption of coreactant and ECL resonance energy transfer. And the ECLPDI-CH3/ECLg-C3N4 showed ultrasensitive linear response for CEA between 0.1 fg mL−1 and 1 ng mL−1 with detection limit 0.052 fg mL−1 according to IUPAC criterion. In addition, the proposed ratiometric biosensor exhibited good recovery in human serum samples. •PDI-CH3 and g-C3N4 produced potential-resolved ECL with coreactant K2S2O8 between 0 and -1.2 V.•There was good overlap between the ECL spectrum of g-C3N4 and the absorption spectra of PDI-CH3.•PDI-CH3 highly quenched the ECL of g-C3N4 by competitive consumption of K2S2O8 and ECL-RET in ratiometric biosensor.