Electropotential-Inspired Star-Shaped Gold Nanoconfined Multiwalled Carbon Nanotubes: A Proof-of-Concept Electrosensoring Interface for Lung Metastasis Biomarkers

Herein, an innovative way of designing a star-shaped gold nanoconfined multiwalled carbon nanotube-engineered sensoring interface (AuNS@MISCNT//GCE) is demonstrated for quantification of methionine (MTH); a proof of concept for lung metastasis. The customization of the AuNS@MWCNT is assisted by surface electro-chemistry and thoroughly discussed using state-of-the-art analytical advances. Micrograph analysis proves the protrusion of nanotips on the surface of potentiostatically synthesized AuNPs and validates the hypothesis of Turkevich seed (AuNP)-mediated formation of AuNSs. In addition, a facile synthesis of electropotential-assisted transformation of MWCNTs to luminescent nitrogen-doped graphene quantum dots (N-d-GQDs avg. similar to 4.3 run) is unveiled. The sensor elucidates two dynamic responses as a function of C-MTH ranging from 2 to 250 mu M and from 250 to 3000 mu M with a detection limit (DL) of similar to 0.20 mu M, and is robust to interferents except for tiny response of a similar -SH group bearing Cys (<9.00%). The high sensitivity (0.44 mu A.mu M-1. cm(-2)) and selectivity of the sensor can be attributed to the strong hybridization of the Au nanoparticle with the sp(2) C atom of the MWCNTs, which makes them a powerful electron acceptor for Au-SH-MTH interaction as evidenced by density functional theory (DFT) calculations. The validation of the acceptable recovery of MTH in real serum and pharma samples by standard McCarthy-Sullivan assay reveals the holding of great promise to provide valuable information for early diagnosis as well as assessing the therapeutic consequence of lung metastasis.

Automated summary

An innovative design method for a gold nanotube sensor interface is demonstrated, allowing for accurate measurement of methionine and potential diagnosis of lung metastasis. The sensor shows high sensitivity and selectivity, and has been validated in real samples.