Cellulose bio-nanocomposites as test-strips for protein cancer biomarkers

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Molecularly imprinted polymer for Mucin 4 (MUC4) biomarker

Publication . Piloto, A.M.L.; Cerqueira, N.; Sales, Goreti

(Introduction) Molecularly imprinted polymers (MIPs) were synthesized around quantum dots (QDs) to detect the protein biomarker MUC4, which is associated with pancreatic cancer (Kauretal.,2022; Mehrotraetal.,2024). In this approach, MIPs serve as biorecognition elements and are conjugated with cadmium telluride QDs to form the sensing system. The fluorescence of these imprinted polymers is quenched as MUC4 concentrations increase, demonstrating a linear response within the range of 0.12 ng/mL to 16.9 ng/mL in human serum. This range is below the pancreatic cancer diagnostic cut-off values (1.2 to 1.3 ng/mL). The MIPs exhibit good stability and selectivity for MUC4 compared to non-imprinted controls. Additionally, theoretical studies provide valuable insights for the prediction of the functional structure of MIPs, enhancing its selectivity for the target, while reducing time and costs associated with laborious benchtop assays, which may provide an effective tool for tailoring MIPs to other biomarkers for clinical diagnosis.

2024Conference object

Open access

Sensitive ratiometric imprinted hydrogel for the detection of matrix metalloproteinase 7 (MMP7) biomarker

Publication . Piloto, Ana Margarida L.; Ribeiro, David S.M.; Santos, João L.M.; Sales, Goreti

A dual-emissive fluorescent probe has been developed for the sensitive and selective detection of matrix metalloproteinase 7 (MMP7), a protein biomarker associated with pancreatic cancer1,2. The resultant materials were designated as imprinted ratiometric hydrogels (imprinted rHGs). The fluorescence quenching of the imprinted rHGs occurred with increasing concentrations of MMP7, showing linearity in the range [1.49 x 10-11 – 1.92 x 10-9] g/mL in 1000-fold diluted human serum in PBS 10mM pH 5.8. Overall, the imprinted rHGs developed in this work presented increased selectivity for the MMP7 protein over raw emitting QDs nanoparticles and higher sensitivity comparatively to the non-imprinted rHGs.

2024Conference object

Open access

Cellulose‑based hydrogel on quantum dots with molecularly imprinted polymers for the detection of CA19‑9 protein cancer biomarker

Publication . Piloto, Ana Margarida L.; Ribeiro, David S.M.; Rodrigues, S. Sofia M.; Santos, João L.M.; Sampaio, Paula; Sales, Maria Goreti Ferreira

Molecularly imprinted polymers (MIPs), were successfully assembled around quantum dots (QDs), for the detection of the carbohydrate antigen CA19-9, a biomarker associated with pancreatic cancer (PC). The imprinted materials MIP@QDs were incorporated within cellulose hydrogels and designated as imprinted hydrogels (iHGs). The concept is to use MIPs which function as the biorecognition elements, conjugated to QDs as the sensing system. The fluorescence quenching of the iHGs occurred with increasing concentrations of CA19-9, showing linearity in the range 2.76 × 10−2 – 5.23 × 102 U/ml, in a 1000-fold diluted human serum. The iHGs show a linear response below the cutoff values for pancreatic cancer diagnosis (< 23 U/ml), a limit of detection of 1.58 × 10−3 U/ml and an imprinting factor (IF) of 1.76. Moreover, they exhibit stability and selectivity towards CA19-9, when compared with the non-imprinted controls, here designated as non-imprinted hydrogels (non-iHGs). In conclusion, this work demonstrates that the conjugation of MIPs to QDs increases the sensitivity and specificity of the developed sensing system for optical detection methods within clinical significance ranges. This fact shows potential for the iHGs to be applied as a sensitive, low-cost format for point-of-care tests (PoCTs).

2024Lecture

Open access