Quantitative real-time detection of carcinoembryonic antigen (CEA) from pancreatic cyst fluid using 3-D surface molecular imprinting

Abstract

In this study, a sensitive, yet robust, biosensing system with real-time electrochemical readout was developed. The biosensor system was applied to the detection of carcinoembryonic antigen (CEA), which is a common marker for many cancers such as pancreatic, breast, and colon cancer. Real time detection of CEA during a medical procedure can be used to make critical decisions regarding further surgical intervention. CEA was templated on gold surface (RMS roughness ∼3-4 nm) coated with a hydrophilic self-assembled monolayer (SAM) on the working electrode of an open circuit potentiometric network. The subsequent removal of template CEA makes the biosensor capable of CEA detection based on its specific structure and conformation. The molecular imprinting (MI) biosensor was further calibrated using the potentiometric responses in solutions with known CEA concentrations and a detection limit of 0.5 ng ml(-1) was achieved. Potentiometric sensing was then applied to pancreatic cyst fluid samples obtained from 18 patients when the cyst fluid was also evaluated using ELISA in a certified pathology laboratory. Excellent agreement was obtained between the quantitation of CEA obtained by both the ELISA and MI biosensor detection for CEA. A 3-D MI model, using the natural rms roughness of PVD gold layers, is presented to explain the high degree of sensitivity and linearity observed in those experiments.

Rapid fluorescence immunoassay of benzo[a]pyrene in mainstream cigarette smoke based on a dual-functional antibody–DNA conjugate

“…The results showed that the immunoassay of 2-ring and 3-ring PAHs, naphthalene and anthracene, had a very small cross reaction (<1%). The four-ring compounds, pyrene, ben[a]anthracene and chrysene, had moderate cross-reactivity (15,22 and 31% for pyrene, ben[a]anthracene and chrysene, respectively). However, the benzo[b]uoranthene, which possessed ve rings like BaP, had a very high cross-reactivity of 61%.…”

“…In addition, targeting BaP as a method of analysis also includes the application of a series of monoclonal antibodies generated by BaP derivatives, [9][10][11] and then a variety of immunochemical detection methods were developed for rapid detection of PAHs, such as enzyme-linked immunosorbent assay (ELISA), molecular imprinting biosensors, surface Plasma resonance immunosensors, uorescent immunoassays and electrochemical immunoassays. [12][13][14][15][16] Among these methods, uorescent immunoassay has become a promising method due to the recent development of new uorescent labeling techniques such as quantum dots, carbon nanotubes, and DNA labels, which have been used to improve the stability and sensitivity. [17][18][19] Among these new uorescence labeling techniques, uorescence immunoassays employing antibody-DNA/ dye immune complexes make uorescence amplication possible and more compatible with protein chips and lateral ow immunoassays.…”

Surface-imprinted biosensors for the detection of proteins, cancer markers and viruses

“…The recognition element is responsible for selective binding of the target analytes, and the transducer produces the signal in accordance with the binding amount of the target analyte. The signal transition principle of the transducer can be based on the mass [1], optical [2,3], sound [4][5][6], fluorescence [7][8][9], electrochemical [10][11][12][13][14][15][16][17][18][19][20][21][22][23], or thermal response [24]. The recognition elements are usually biological agents which can be enzymes [25][26][27], antibodies [28][29][30], DNA [26,28,31,32], microbes [33][34][35][36][37][38][39][40][41], plant or animal cells [25,42,43], etc.…”

Recent progress on nanostructured conducting polymers and composites: synthesis, application and future aspects

“…Zhang et al fabricated a potentiometric immunosensor for the detection of a cardiac biomarker-Troponin I-T-C with PANI/ DNNSA as a transducing layer. Different from traditional potentiometric sensors based on potentiometric response from analyte binding [333,334], this sensor depends on enzymatic redox reaction catalyzed on the sensing surface. It has a significantly low limit of detection (5 pg mL −1 or 56 fmol L −1 ) and a wide dynamic range (6 orders of magnitudes), making it an ideal substitute for conventional immunoassays currently used in clinical settings [335].…”