Magnetic Particle-Based Sandwich Sensor with DNA-Modified Carbon Nanotubes as Recognition Elements for Detection of DNA Hybridization

Abstract

In this contribution, we design a visual sensor for DNA hybridization with DNA probe-modified magnetic particles (MPs) and multiwalled carbon nanotubes (MWNTs) without involving a visual recognition element such as fluorescent/chemiluminescent reagents. It was found that DNA probe-modified MWNTs, which could be dispersed in aqueous medium and have strong light scattering signals under the excitation of a light beam in the UV-vis region, could connect with DNA probe-modified MPs together in the presence of perfectly complementary target DNA and form a sandwich structure. In a magnetic field, the formed MP-MWNT species can easily be removed from the solution, resulting in a decrease of light scattering signals. Thus, a magnetic particle-based sandwich sensor could be developed to detect DNA hybridization by measuring the light scattering signals with DNA-modified MWNTs as recognition elements. Experiments showed that the DNA-modified MPs sensor could be reused at least 17 times and was stable for more than 6 months.

Magnetic solids in analytical chemistry: A review

“…One of the objectives of these devices is to decrease the limits of detection so that they are useful for analyzing real samples [193,194]. The use of modified magnetic particles in sensing is targeted at developing more specific, stable and reproducible devices [195]. In addition, magnetic particles (generally magnetite) provide a good microenvironment for retaining bioactivity, increased protein loading, and are a renewable alternative [196,197].…”

Magnetic Fe3O4-Based Sandwich-Type Biosensor Using Modified Gold Nanoparticles as Colorimetric Probes for the Detection of Dopamine

“…Magnetic Fe 3 O 4 particles were prepared via the co-precipitation [34]. Briefly, FeCl 3 ·6H 2 O (5.40 g) and FeSO 4 ·7H 2 O (2.78 g) were dissolved under a N 2 atmosphere in 100 mL of deoxygenated water, which had been bubbled for 15 min with nitrogen gas.…”

Carbon Nanotubes in Biomedicine and Biosensing

“…Even though preliminary at this stage, these results indicate the potential use of CNTs for the treatment of HIV. Drouvalakis, Bangsaruntip, Hueber, Kozar, Utz, & Dai, 2008;Hu, Huang, Li, Ling, Liu, Fei, et al, 2008) Among widespread nanoscale building blocks, such as organic or inorganic nanowires and nanodots, CNTs are considered as one of the most versatile because of their superior mechanical and electrical properties and geometrical perfection. DNA analysis plays an ever-increasing role in a number of areas related to human health including diagnosis of infectious diseases, genetic mutations, drug discovery, food security, and warning against biowarfare agents.…”

“…Furthermore, a visual sensor has been designed to detect DNA hybridization by measuring the light scattering signal with DNA modified MWCNT as recognition element as shown in figure 2. (Hu, et al, 2008) This sensor can be reused for at least 17 times and is stable for more than 6 months. (T1), (c) SWCNT, and (d_) SWCNT + 300 nM T1.…”