Antibody Biomimetic Material Made of Pyrrole for CA 15-3 and Its Application as Sensing Material in Ion-Selective Electrodes for Potentiometric Detection

Abstract

This work reports a very simple approach for creating a synthetic antibody against any protein of interest and its application in potentiometric transduction. The selected protein was Breast Cancer Antigen (CA 15-3), which is implicated in breast cancer disease and used to follow-up breast cancer patients during treatment. The new material with antibody-like properties was obtained by molecular-imprinting technology, prepared by electropolymerizing pyrrol (Py, 5.0 × 10−3 mol/L) around Breast Cancer Antigen (CA 15-3) (100 U/mL) on a fluorine doped tin oxide (FTO) conductive glass support. Cyclic voltammetry was employed for this purpose. All solutions were prepared in 4-(2-Hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) buffer, of pH 6.5. The biomarker was removed from the imprinted sites by chemical action of ethanol. The biomimetic material was then included in poly vinyl chloride (PVC) plasticized membranes to act as potentiometric ionophore, having or not a lipophilic ionic additive added. The corresponding selective electrodes were evaluated by calibration curves (in buffer and in synthetic serum) and by selectivity testing. The best analytical performance was obtained by selective electrodes including the plastic antibody and no lipophilic additive. The average limits of detection were 1.07 U/mL of CA 15-3, with a linear response from 1.44 to 13.2 U/mL and a cationic slope of 44.5 mV/decade. Overall, the lipophilic additives yielded no advantage to the overall potentiometric performance. The application of the MIP-based electrodes to the analysis of spiked synthetic serum showed precise and accurate results.

A Review of Biosensors for Detecting Tumor Markers in Breast Cancer

“…The detection limit was 1.6 ng L −1 and the limit of quantification was 5.2 ng mL −1 . In addition, Santos et al [ 116 ] prepared a molecularly imprinted polymer using CA15-3 as a template by electropolymerizing pyrrol around CA15-3 on a fluorine doped tin oxide (FTO) conductive glass support to detect CA15-3. The detection of the concentration of the target was accomplished by potentiometric titration.…”

Molecularly Imprinted Polymers for the Determination of Cancer Biomarkers

“…However, with further studies, this new biosensor appears to have the potential for point-of-care use, as it has a wide concentration range that allows direct analysis of samples above or well below the cut-off value of 30 U/mL. Santos et al [ 54 ] also conducted a polymer to develop a sensor for CA15-3. Pyrrole was electropolymerised on a fluorine-doped tin oxide conductive glass.…”

Review—Bio-Nanosensors: Fundamentals and Recent Applications

“…171 An anti-body like ionophore layer was used as a carrier molecule between the solution and membrane in the potentiometric detection of CA 15-3 in serum. 172 Isildak et al showed that 4-hydroxybenzo-15-crown-5 ether can be used as ionophore in PVC membrane beryllium ISE for the detection of Be 2+ in solutions. 173 Enzymatic biocatalytic precipitation and nanogold labeling techniques have been used to improve the sensitivity in potentiometric immunosensors response.…”