A lateral flow biosensorbased on an immuno-chromatographic assay has been developed forthe detection of DNA- bindingproteins. The biosensoris composed offour parts: asample pad, aconjugate pad, astrip ofnitrocellulose membrane and an absorbent pad. A DNAprobe containing aspecific protein bindingconsensus sequence is coated onto gold nanoparticles, while an antibody against the DNA- binding proteinis immobilized onto atest zone ofthe nitrocellulose membrane. The target proteinbinds to the protein binding DNAsequence that is coated on the gold nanoparticles to form nanoparticle- DNA- proteincomplexes, and the complexes are then captured by the antibody immobilized on the test zone to form ared line forvisual detection ofthe target protein. This biosensorwas successfully applied to a DNA- binding protein, c- jun, and the developed biosensorallows forthe rapid detection ofdown to 0.2 footprint unit of c- jun proteinwithin 10 min. This biosensorwas verified using HeLa cells and it visually detected c- junactivity in 100 mu g ofcrude cell lysate protein. The antibody against c- junused in the biosensorcan distinguish c- junfrom other nonspecific proteins, with high specificity. ( C) 2011 Elsevier B.V. All rights reserved.