Xuanxuan Hao,Zhimin Liu,Yaxin Li,Waner Hou,Tongtong Zheng,Leqian Hu
In this study, a near-infrared (NIR) electrochemiluminescence (ECL) emitter CdIn 2 S 4 was synthesized by a convenient hydrothermal strategy. The ECL properties of the obtained CdIn 2 S 4 were examined in the presence of potassium persulfate coreactant at an excitation potential of − 1.25 V. The low trigger voltage of CdIn 2 S 4 may be ascribed to its lower bandgap. This lower excitation potential could effectively reduce the side-effects induced by high voltages, while maintaining the biological activity of antibodides and antigens. The ECL features of CdIn 2 S 4 were also investigated, demonstrating that CdIn 2 S 4 exhibited excellent NIR characteristics, and surface state transitions led to the ECL emission. Importantly, CdIn 2 S 4 was introduced into ECL and electrochemical impedance spectroscopy (EIS) to establish a dual-mode immunosensing interface. Meanwhile, AuNPs@g-C 3 N 4 with excellent properties were used to promote electron transmission and increase the immobilization amount of zearalenone (ZEA) antibodies in the dual-mode sensing system. The developed immunosensing strategy displayed superior sensing performance in ZEA analysis. The detection limits of ZEA were 30 fg mL −1 (ECL model) and 10 fg mL −1 (EIS model), respectively. The desirable recovery results of ZEA in corn samples prove the application potential of the NIR emitter CdIn 2 S 4 in developing a dual-mode immunosensing system for early real-time use.
Hui Zhong,Yonghua Yuan,Min Qing,Jianli Zuo,Yueyuan Li,Lijuan Bai
The extracellular domain of the human epidermal growth factor receptor (HER2-ECD) is a breast cancer biomarker. Accurate and sensitive detection of HER2-ECD concentration in serum is crucial in the diagnosis and patient follow-up. Herein, an “off–on” type electrochemiluminescence (ECL) aptasensor based on the resonance energy transfer (RET) between AuPt@ZIF-67 and AuNPs/g-C3N4/PDDA was developed for detecting HER2-ECD. First, AuNP-modified g-C3N4 (AuNPs/g-C3N4/PDDA), as a signal substrate, generates ECL signals under the co-reactant peroxodisulfate (S2O82–) in a specific potential range and shows significantly enhanced signal strength and stability. Then, AuPt@ZIF-67 expeditiously quenched the ECL signal of AuNPs/g-C3N4/PDDA because of ECL resonance energy transfer (ECL-RET) between AuPt@ZIF-67 and AuNPs/g-C3N4/PDDA. We designed a new aptasensor detection platform for HER2-ECD detection. After specific binding of the aptamer with HER2-ECD, the AuPt@ZIF-67 content in the system decreased, and the ECL response recovered. The biosensor demonstrated a linear range of HER2-ECD detection between 100 fg/mL and 100 ng/mL under ideal circumstances, with a low detection limit of 17.3 fg/mL. Furthermore, this biosensor was successfully tested in human serum samples. This strategy, as a novel ECL system with satisfactory stability and excellent sensitivity, can realize the detection of other biological molecules by changing the probe, which is a promising method.
Xuejiao Liu,Qiaoe Wang,Jun Chen,Xu Chen,Wensheng Yang
Highly sensitive determination of tumor exosomes is significant for early diagnosis of cancers and precision therapy. Herein, a sandwich peptide-based electrochemiluminescence (ECL) biosensor was developed for determination of phosphatidylserine (PS)-positive exosomes, a promising biomarker for early diagnosis of ovarian malignancy. A PS-specific binding peptide with high affinity was immobilized on Au nanoflowers (AuNFs) modified biosensing interface for recognition and capture of exosomes. Meanwhile, g-C 3 N 4 nanosheet loaded with luminol capped AuNPs (Lum-AuNPs@g-C 3 N 4 ) nanocomposite was used as the ECL signal nanoprobe. The g-C 3 N 4 nanosheets with large surface area were not only utilized as the carrier to immobilize more peptides for recognition of exosomes but also used to catalyze co-reactant H 2 O 2 decomposition to achieve the ECL signal amplification of luminol-H 2 O 2 system. Under optimal conditions, the biosensor showed superior performances compared with most currently available methods, including wider linear range across 5 orders of magnitude and a lower detection limit (LOD) down to 39 particles μL −1 . Moreover, the biosensor could be applicable for determination of exosomes in complex biological samples. This study indicates the combination of peptide recognition with nanoprobe as a label for signal amplification in sandwich ECL biosensing is a great promising strategy for sensitive and cost-effective determination of exosomes.
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