Method for detecting cocaine by using quartz crystal microbalance

Abstract

The invention discloses a method for detecting cocaine by using a quartz crystal microbalance. The method comprises the steps of: I, preparing a QCM (Quartz Crystal Monitor) chip with self-assembled DNA on the surface of the QCM chip; II, closing excessive sites on the surface of the chip; III, preparing an initiator-labeled DNA (Deoxyribonucleic Acid) solution; IV, jointly hatching the closed chip by using an aptamer DNA solution and the initiator-labeled DNA solution, placing the closed chip into a reactor of the quartz crystal microbalance, introducing a buffer solution, and reading a frequency F1; V, taking out the chip for a surface initiated polymerization reaction; and VI, placing the chip subjected to the surface initiated polymerization reaction into the reactor, introducing the buffer solution, reading a frequency F2, then introducing a detecting object, reading a frequency3, calculating differences delta F' and delta F'' between F2 and F1 as well as between F2 and F3, and determining that the detecting object contains the cocaine when the ratio of delta F'' to delta F' is not less than 30%. As the quartz crystal microbalance is used as a detection tool, the method for detecting the cocaine by using the quartz crystal microbalance has the advantages of real-time detection and the like.

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