Jiang B, Zhang T, Liu S, Sheng Y, Hu J. Polydopamine-assisted aptamer-carrying tetrahedral DNA microelectrode sensor for ultrasensitive electrochemical detection of exosomes.
J Nanobiotechnology 2024;
22:55. [PMID:
38331774 PMCID:
PMC10854160 DOI:
10.1186/s12951-024-02318-6]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 01/26/2024] [Indexed: 02/10/2024] Open
Abstract
BACKGROUND
Exosomes are nanoscale extracellular vesicles (30-160 nm) with endosome origin secreted by almost all types of cells, which are considered to be messengers of intercellular communication. Cancerous exosomes serve as a rich source of biomarkers for monitoring changes in cancer-related physiological status, because they carry a large number of biological macromolecules derived from parental tumors. The ultrasensitive quantification of trace amounts of cancerous exosomes is highly valuable for non-invasive early cancer diagnosis, yet it remains challenging. Herein, we developed an aptamer-carrying tetrahedral DNA (Apt-TDNA) microelectrode sensor, assisted by a polydopamine (PDA) coating with semiconducting properties, for the ultrasensitive electrochemical detection of cancer-derived exosomes.
RESULTS
The stable rigid structure and orientation of Apt-TDNA ensured efficient capture of suspended exosomes. Without PDA coating signal amplification strategy, the sensor has a linear working range of 102-107 particles mL-1, with LOD of ~ 69 exosomes and ~ 42 exosomes for EIS and DPV, respectively. With PDA coating, the electrochemical signal of the microelectrode is further amplified, achieving single particle level sensitivity (~ 14 exosomes by EIS and ~ 6 exosomes by DPV).
CONCLUSIONS
The proposed PDA-assisted Apt-TDNA microelectrode sensor, which integrates efficient exosome capture, sensitive electrochemical signal feedback with PDA coating signal amplification, provides a new avenue for the development of simple and sensitive electrochemical sensing techniques in non-invasive cancer diagnosis and monitoring treatment response.
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