ANYL 444 |
| We show that small ssDNA (10 nt) can be reliably detected by hybridizing directly with its complementary strand (15 to 18 nt) immobilized on a piezoelectric-excited millimeter cantilever (PEMC) sensor by measuring the sensor's resonance frequency. The mass sensitivity of the PEMC sensor is ~0.3 fg/Hz. Detection at 1 fM to 1 nM concentration was measured in both hybridizing buffer and in 50% human serum in a flow circuit at 1 mL/min flow rate, using a fromat somewhat similar to a liquid chromatograph.. Both buffer controls and non complementary strands gave essentially zero response. The sensor distinguishes single nucleotide polymorphism in buffer at 1 fM, and detects complementary strand at 1 pM in presence of copious amounts (10,000 X) of non complementary strands. One application of the PEMC-based DNA detection that will be demonstrated is E coli O157:H7 via its STX1 gene in both clean and food matrix. The method does not use any labeled reagents. |
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Analytical Approaches
9:00 AM-12:00 PM, Thursday, August 23, 2007 BCEC -- 104A, Oral
Division of Analytical Chemistry |