Highly specific lubricin-lectin electrochemical sensor for glycoprotein cancer biomarker detection
Miaosi Li, Chathurika D. Abeyrathne, Daniel Langley, Luke R. Cossins, Anushka N. Samudra, George W. Green, Simon E. Moulton, Saimon Moraes Silva
Abstract
Electrochemical glycoprotein sensors have proven to be a great alternative for the detection and characterization of cancer, therapeutic design, and monitoring. A combination of the glycoproteins lubricin (LUB) and peanut agglutinin (PNA) has been successfully implemented for the detection of tumour-associated short glycans directly in bodily fluids, e.g. whole blood. However, such an approach has so far only been studied using a surface-bound redox mediator engineered with the recognition element, PNA. In this paper, we extend the lubricin-peanut agglutinin (LUB-PNA) interface for monitoring glycan binding interactions using redox species in solution. Cyclic voltammetry and electrochemical impedance spectroscopy measurements using the LUB-PNA interface showed that faradaic electron transfer of ferrocyanide redox species in solution is altered in presence of the glycoprotein containing cancer-associated T-antigen glycoprotein (asialofetuin, ASF), while it does not alter in presence of the sialylated glycoform of ASF, fetuin (FET), bovine serum albumin (BSA) and Tn-antigen. The limit of detection (LoD) of ASF is 39 nM in PBS. In addition, this highly specific LUB-PNA sensor allows for the detection of ASF in human blood.