Sensitive detection and glycoprofiling of a prostate specific antigen using impedimetric assays

Abstract

This study presents a proof-of-concept for the development of an impedimetric biosensor for ultra-sensitive glycoprofiling of prostate specific antigen (PSA). The biosensor exhibits three unique characteristics: (1) analysis of PSA with limit of detection (LOD) down to 4 aM; (2) analysis of the glycan part of PSA with LOD down to 4 aM level and; (3) both assays (i.e., PSA quantification and PSA glycoprofiling) can be performed on the same interface due to label-free analysis.

Sweet characterisation of prostate specific antigen using electrochemical lectin‐based immunosensor assay and MALDI TOF/TOF analysis: Focus on sialic acid

“…In a previous pilot study, we showed for the first time that label-free impedimetric detection in a sandwich configuration with an immobilised antibody and lectin applied to complete a sandwich around captured PSA can be applied both for detection of the level of PSA and for glycoprofiling of PSA´s glycan on the same surface [41]. In this work, we aimed to extend such study by application of three different lectins for glycoprofiling of PSA´s glycan with the impedimetric biosensor working in a sandwich configuration and to validate the biosensor results by glycoprofiling of PSA´s with MALDI TOF/TOF.…”

Prostate cancer diagnostics: Clinical challenges and the ongoing need for disruptive and effective diagnostic tools

“…A recent publication by Tkac's group described the developed of a lectin-based impedimetric biosensor for PSA quantification (down 4 aM) and glycoprofiling on the same interface. SNA lectin (sugar-binding protein),was used for ‗in-situ' glycoprofiling of PSA glycan, while simultaneously detecting PSA concentrations down to aM levels (Pihíková et al, 2016). α2,6-linked sialic acid is lower in serum PSA from prostate cancer patients in comparison with BPH, while α2,3-linked sialic acid is more abundant in PSA from cancer patients (Meany et al, 2008).…”

Determining the binding affinities of prostate‐specific antigen to lectins: SPR and microarray approaches

“…Jolly et al and Pihikova et al demonstrated that PSA from healthy individuals has high content of ␣-(2,6) sialic acid assessed by strong interaction of PSA with SNA, lectin preferentially binding to ␣-(2,6) linked sialic acid. On the other hand, MAA II lectin preferentially binding to ␣-(2,3) linked sialic acid did not interact with fPSA [33,34]. The increased ␣2-3 sialylation and fucosylation in PCa patients has been reported [12,[35][36][37] as well as alteration in branching of N-acetylglucosamine [38,39] or alteration of mannose or galactose residues [40].…”