HIGH-AFFINITY RNA AS A RECOGNITION ELEMENT IN A BIOSENSOR

A biosensor for L-adenosine employing high-affinity RNA as binder is r eported. Real-time measurement is obtained using total internal reflec tion fluorescence in a fiber-optic format. High-affinity RNA was attac hed to the core of a multimode fiber via and avidin-biotin bridge. The sensor measures binding of FITC-labeled L-adenosine. The interaction was fully characterized by the determination of association and dissoc iation rates: k(D) = 0.0119 s(-1); k(A) = 2200 M-1 s(-1). Competitive inhibition with L-adenosine enables this device to detect L-adenosine in the submicromolar range.