Abstract

It is becoming understood that microRNAs hold great promise for noninvasive liquid biopsies for screening for different types of cancer, but current state-of-the-art RT-PCR and microarray techniques have sensitivity limitations that currently restrict their use. Herein, we report a new transduction mechanism involving delocalization of photoexcited conduction electrons wave function of gold triangular nanoprism (Au TNP) in the presence of -ssDNA/microRNA duplexes. This plasmoelectronic effect increases the electronic dimension of Au TNPs and substantially affects their localized surface plasmon resonance (LSPR) properties that together allow us to achieve a sensitivity for microRNA assay as low as 140 zeptomolar concentrations for our nanoplasmonic sensors. We show that the position of a single base-pair mismatch in the -ssDNA/microRNA duplex dramatically alters the LSPR properties and detection sensitivity. The unprecedentedly high sensitivity of nanoplasmonic sensors has allowed us to assay four different microRNAs (microRNA-10b, -182, -143, and -145) from bladder cancer patient plasma (50 μL/sample). For the first time, we demonstrate the utility of a label-free, nanoplasmonic sensor in quantification of tumor suppressor microRNAs, the level of tumor suppressor microRNAs goes down in a cancer patient as compared to normal healthy individuals, in metastatic and nonmetastatic bladder cancer patient plasma. Our statistical analysis of patient samples unequivocally suggests that the tumor suppressor microRNAs are more specific biomarkers ( p-value of <0.0001) than oncogenic microRNAs for differentiation between metastatic and nonmetastatic bladder cancer, and nonmetastatic cancer from healthy individuals. This work demonstrating the electron wave functions delocalization dependent ultrasensitive LSPR properties of noble metal nanoparticles has a great potential for fabrication of miniaturized and extremely powerful sensors to investigate microRNA properties in other cancers (for example breast, lung, and pancreatic) through liquid biopsy.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.