Molecular Pincers: Antibody-Based Homogeneous Protein Sensors

• Published in: Analytical chemistry (Washington) Vol. 80; no. 13; pp. 5152 - 5159
• Main Authors: Heyduk, Ewa, Dummit, Benjamin, Chang, Yie-Hwa, Heyduk, Tomasz
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01-07-2008
• Subjects: Analytical biochemistry: general aspects, technics, instrumentation; Analytical chemistry; Analytical, structural and metabolic biochemistry; Antibodies, Monoclonal - chemistry; Antibodies, Monoclonal - immunology; Antibody Specificity; Biological and medical sciences; Biosensing Techniques - methods; Biosensors; C-Reactive Protein - analysis; C-Reactive Protein - immunology; Chemistry; Enzyme-Linked Immunosorbent Assay - methods; Exact sciences and technology; Fluorescence Resonance Energy Transfer - methods; Fluorescent Dyes - chemistry; Fundamental and applied biological sciences. Psychology; General, instrumentation; NF-kappa B - analysis; NF-kappa B - immunology; Oligonucleotides - chemistry; Proteins; Proteins - analysis; Proteins - immunology; Spectrometric and optical methods; Troponin I - analysis; Troponin I - immunology; Tumor Suppressor Protein p53 - analysis; Tumor Suppressor Protein p53 - immunology; Nanometer scale; Annealing; Sensitivity; Antibody; Enzyme; Oligonucleotide; Chemical sensor; Protein; Fluorescence spectrometry
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac8004154

We describe here a new homogeneous antibody-based protein sensor design (molecular pincers) that allows rapid and sensitive detection of a specific protein in solution. In the presence of the target protein these sensors produce fluorescence signal derived from target-dependent annealing of short complementary fluorochrome-labeled oligonucleotides attached to a pair of target-specific antibodies via nanometer-scale flexible linkers. The sensors allow near-instantaneous detection of the target with sensitivity and specificity approaching that of enzyme-linked immunosorbent assay (ELISA) but requiring no sample manipulation other then the addition of the sample to the sensor mix. We used cardiac troponin I and C-reactive protein as the targets to validate these desirable properties of the sensors. Due to the availability of antibodies to thousands of interesting targets and the straightforward design blueprint of the sensors we expect their wide-ranging applications in research and medical diagnosis, especially when simplicity, high throughput, and short detection time are essential.