Fast and Accurate Control Strategy for Portable Nucleic Acid Detection (PNAD) System Based on Magnetic Nanoparticles

Abstract

Portable nucleic acid detection (PNAD) systems are performed for sample processing, amplification and detection automatically in an individual device realizing "sample in, answer out." For this goal, numerous function modules should be integrated in a diminutive device, in which temperature controller is one of the most important modules. In a nucleic acid detection process, both sample processing and polymerase chain reaction (PCR) require fast and accurate temperature control to increase concentration and purity of the extraction product and to improve amplification efficiency. In this paper, a dual-channel temperature controller for PNAD systems is developed, which contains a printed circuit board (PCB) and an integrated control program with a fast and accurate control strategy. According to the principle of nucleic acid detection based on magnetic nanoparticles, the controller can work in different modes such as high-precision heating control for nucleic acid extraction, rapid thermal cycle control for PCR, and rate adjustable constant heating/cooling control for melting curve. Evaluatively, the average heating/cooling rate of the module can exceed about 6 C/s, while the temperature fluctuation was less than ± 0.1°C, which can meet the demands of PNAD systems very well.

Applications of Aptamer-Bound Nanomaterials in Cancer Therapy

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Postsynthetic Modification of the Magnetic Zirconium–Organic Framework for Efficient and Rapid Solid-Phase Extraction of DNA

“…Normally, human biological samples containing multiple components require a pretreatment procedure to isolate target DNA before detection . In recent years, solid-phase extraction (SPE), solid-phase microextraction, magnetic solid-phase extraction (MSPE), − and liquid–liquid extraction have been utilized for DNA extraction . As a novel SPE technology, MSPE considerably simplifies the extraction procedure with simple instrument and high efficiency .…”

New Ultrasensitive Sandwich-Type Immunoassay of Dendritic Tri-Fan Blade-like PdAuCu Nanoparticles/Amine-Functionalized Graphene Oxide for Label-Free Detection of Carcinoembryonic Antigen

“…The sensitive and accurate detection of tumor markers in serum is vital for early diagnoses and clinical treatment of tumors [ 4 ]. To date, various sophisticated methods have been used to determine biomarkers, including immunohistochemistry (IHC) [ 5 ], real-time PCR [ 6 ], microarray chips [ 7 ], fluorescence in situ hybridization (FISH) [ 8 , 9 ], chromogenics [ 10 ], chemiluminescence immunoassay [ 11 , 12 ] and electrochemistry [ 13 ]. Among these strategies, as we know, high specificity is the reason why enzyme-linked immunosorbent assay (ELISA) has been used as the conventional method for the detection of cancer biomarkers.…”