We describe a fresh type of biosensor for the detection of p53 antibodies bound to peptides immobilized on functionalized gold microelectrodes. desorption ionization (SAMDI) mass spectrometry, and adhesion pull-off force by atomic force microscopy (AFM). This transduction method will lead to fast and accurate diagnostic tools for the early detection of cAMPS-Sp, triethylammonium salt cancer and other diseases. Keywords: self-assembly, characterization tools, biomedical applications, cancer prognostics, biosensors Introduction The identification and measurement of biomarkers is critical to a broad range of methods that diagnose and monitor many diseases. 1C3 Proteins are the most widely used and studied biomarkers, Mouse monoclonal to CD19.COC19 reacts with CD19 (B4), a 90 kDa molecule, which is expressed on approximately 5-25% of human peripheral blood lymphocytes. CD19 antigen is present on human B lymphocytes at most sTages of maturation, from the earliest Ig gene rearrangement in pro-B cells to mature cell, as well as malignant B cells, but is lost on maturation to plasma cells. CD19 does not react with T lymphocytes, monocytes and granulocytes. CD19 is a critical signal transduction molecule that regulates B lymphocyte development, activation and differentiation. This clone is cross reactive with non-human primate as shown in the literature4C6 but serum auto-antibodies are rapidly becoming interesting targets because of their biological and medical relevance.7, 8 Usually, the detection of such antibodies is performed by an enzyme-linked immunosorbent assay (ELISA)9, 10 or another optical-based technology,11, 12 but these methods tend to suffer from low sensitivity and require a fluorescently labeled secondary antibody. Therefore, highly sensitive and direct detection methods13 for antibodies would represent a significant advance in the early detection of cancer and other diseases.1, 3 This article describes the direct detection of an unlabeled14 primary antibody by impedance measurements in undiluted serum samples. We describe a new type of biosensor for the detection of p53 antibodies bound to peptides immobilized on functionalized gold microelectrodes. We are using antibodies as they are large, which is an ideal trait for electrical impedance detection as this is dependent on the analytes size.15 This technique relies on a charged surface to present either an attractive or repulsive force on ions near the microelectrode. Other factors, such as the temperature, pH, or size of the target, can modify the charge-transfer resistance, calcd. for C56H95N9O12S, 1117.68, found 1118.5699 [M + H]+; Compound 2: Purity of 98% (calcd. for C43H66N10O9S, 898.47, found 899.3963 [M + H]+; Compound 3: Purity of 98% (after purification) calcd. for C51H80N12O11S, 1068.58, found 1069.5212 [M + H]+; Compound 4: Purity of 92% calcd. for C53H82N14O15S, 1186.58, found 1187.5496 [M + H]+; Compound 5: Purity of 68% (calcd. for C80H104N16O22S, 1672.72, found 1673.6179 [M + H]+; Compound 6: Purity of 92% (after purification) cAMPS-Sp, triethylammonium salt calcd. for C76H114N18O21S, = 1 1646.81, = 2 found 823; Compound 7: Purity of 92% (after purification) calcd. for C79H118N20O25S, 1778.83, found 1779.8872 [M + H]+; Control peptide: Purity of 99% calcd. for C35H54N8O8, 714.41, found 715. and T. Van Zanten, Prof. M. Garca-Parajo, S. Oberhansl, and Prof. J. Samitier, all from the IBEC (Institute for Bioengineering of Catalonia) for allowing us access to the NSOM microscope and for their technical assistance in the microcontact printing assays. This work was partially supported by: IRB Barcelona group: CICYT (CTQ2009-07758), the Generalitat de Catalunya (2009SGR 1024), the Institute for Research in Biomedicine, and the Barcelona Science Park; Lyon group: Surfaces-(bio)Interfaces – Micro & Nano cAMPS-Sp, triethylammonium salt Systmes, SensorART No. 248763, and NATO SfP Project SFPP.NUKR 984173; CNM group: CORBI project and SAF2009-14724-C02-02. The design and fabrication of the microelectrodes was funded by project MICROPLATE CTQ2009-08595. Footnotes Supporting Information Supporting Information is available from the Wiley Online Library or from the author..