Patent ID: 6872810
Filing Date: 2005-03-29
Classification: C12Q,G01N

Abstract:
1. A biochemical sensor system with molecular amplification of a signal for detecting and anal sing a biological entity in a biotic medium, said biological entity being identifiable by at least an elementary strand including a specific nucleotide sequence, said sensor having at its surface a directly or indirectly immobilised detection unit, said detection unit having a complementary nucleotide sequence to that of the biological entity, and said sensor surface being arranged to supply to a detection and measuring device a signal representative of the increase in mass via hybridisation of the biological entity with the detection unit, characterised in that the biotic medium contains monomer compounds and enzymatic catalytic units selected from a DNA strand 3 ′ terminal transferase, a RNA strand polymerase and a synthetase, said enzymatic catalytic units catalyzing from the end of an elementary strand of the biological entity, a polymeric concatenation of said monomer compounds thus locally increasing the mass by a chain extension inducing an amplification of the signal which can be measured at said sensor surface, said sensor system being further characterised in that the compounds allowing the scaffold to be formed are selected from among an antibody modified by a nucleotide, or one of its fragments, DNA dendrimers of suitable size, and metal or semiconductor nanocrystalline compound colloids.