Highly Sensitive Aptasensor for Detecting Cancerous Exosomes Based on Clover-like Gold Nanoclusters

Abstract

Exosome-based liquid biopsy technologies play an increasingly prominent role in tumor diagnosis. However, the simple and sensitive method for counting exosomes still faces considerable challenges. In this work, the CD63 aptamer-modified DNA tetrahedrons on the gold electrode were used as recognition elements for the specific capture of exosomes. Partially complementary DNA probes act as bridges linking trapped exosomes and three AuNP−DNA signal probes. This clover-like structure can tackle the recognition and sensitivity issues arising from the undesired AuNP aggregation event. When cancerous exosomes are present in the system, the high accumulation of methylene blue molecules from DNA− AuNP nanocomposites on the surface of the electrode leads to an intense current signal. According to the results, the aptasensor responds to MCF-7 cell-derived exosomes in the concentration range from 1.0 × 10 3 to 1.0 × 10 8 particles•μL −1 , with the detection limit of 158 particles•μL −1 . Furthermore, the aptasensor has been extended to serum samples from breast cancer patients and exhibited excellent specificity. To sum it up, the aptasensor is sensitive, straightforward, less expensive, and fully capable of receiving widespread application in clinics for tumor monitoring.

Tumor Cell EnVoys Advance the Education of Platelets

“…Diagnostic highly sensitive aptasenors designed to detect CD63 in serum and plasma are also in development. 15 Although still a very challenging approach, requiring a strong knowledge of the normal variation in the platelet mRNA repertoire, 2 the data in this article is supportive of the notion that measurement of cancer markers such as PCA3 in platelets from patients may aid in detection of prostate cancer. Ultimately sequencing of platelet RNA may aid in the diagnosis and clinical decisions around commencement of therapy.…”

Exosomes as Powerful Biomarkers in Cancer: Recent Advances in Isolation and Detection Techniques

“…(Figure 6C). 82 In this study, CD63 aptamer-modified DNA tetrahedrons were used as recognition elements for the specific exosome trapping on gold electrodes. Partially complementary DNA probes act as connectors to connect the captured exosomes to three AuNP-DNA signal probes.…”

Role of aptamer technology in extracellular vesicle biology and therapeutic applications

“…Following EV-CD63 aptamer interaction, a sequential DNA aptamer against mucin 1 (MUC1) in a clove configuration was used to generate a strong electrochemical signal, resulting in an LOD of 1.58 × 10 5 particles per mL using MCF7 cell-derived EVs. 148…”