Carbon Nanopowder-Based Stochastic Sensor for Ultrasensitive Assay of CA 15-3, CEA and HER2 in Whole Blood

Two microsensors obtained by the physical immobilization of 5,10,15,20-tetraphenyl-21H,23H-porphine (TPP) and 5,10,15,20-tetrakis (pentafluorophenyl chloride)-21H,23H-iron (III) porphyrin (Fe(TPFPP)Cl) in carbon nanopowder decorated with gold nanoparticles (AuNp) were designed, characterized, validated and used for the molecular recognition and simultaneous ultrasensitive determination of CEA, CA15-3 and HER2 in whole blood. High sensitivities were recorded for both microsensors. Low limits of quantification were recorded for all biomarkers: CEA (12.8 pg mL(-1) by using Fe(TPFPP)Cl/AuNp, and 190 fg mL(-1) by using TPP/AuNp), CA 15-3 (100 fU mL(-1) for both microsensors) and HER2 (3.9 fg mL(-1) by using Fe(TPFPP)Cl/AuNp, and 35 fg mL(-1) by using TPP/AuNp). A very good correlation between the results obtained using the proposed microsensors and ELISA, certified by the Student t-test, proves that the screening test can be used for ultrasensitive assays of the three biomarkers in whole blood.

Automated summary

In this study, two microsensors were designed, prepared and used for molecular recognition and simultaneous ultrasensitive determination of three biomarkers in whole blood. Both microsensors exhibited high sensitivities and low limits of quantification. The results obtained using the microsensors showed a strong correlation with the ELISA results, indicating the potential of the microsensors for ultrasensitive assays of the biomarkers in whole blood.