Magnetically-refreshable receptor platform structures for reusable nano-biosensor chips

Abstract

We developed a magnetically-refreshable receptor platform structure which can be integrated with quite versatile nano-biosensor structures to build reusable nano-biosensor chips. This structure allows one to easily remove used receptor molecules from a biosensor surface and reuse the biosensor for repeated sensing operations. Using this structure, we demonstrated reusable immunofluorescence biosensors. Significantly, since our method allows one to place receptor molecules very close to a nano-biosensor surface, it can be utilized to build reusable carbon nanotube transistor-based biosensors which require receptor molecules within a Debye length from the sensor surface. Furthermore, we also show that a single sensor chip can be utilized to detect two different target molecules simply by replacing receptor molecules using our method. Since this method does not rely on any chemical reaction to refresh sensor chips, it can be utilized for versatile biosensor structures and virtually-general receptor molecular species.

Magnetically-focusing biochip structures for high-speed active biosensing with improved selectivity

“…Considering that previous optical tweezer experiments with a similar small surface coverage resulted in a rather small distribution of the measured data close to our results, we can expect the multivalency effect in our experiment did not significantly increase the distribution of our data. [23,41] Furthermore, in AFM or optical tweezer measurements, the unbinding force rate during the Kd measurement can significantly affect the measured data, often resulting in a rather large distribution in the measured data. [42] However, the force applied to the bead during the release step in our experiments was estimated as only ~1 pN which was much smaller that the common unbinding forces of about 50-100 pN between abag and should not break the specific bindings between the beads and sensor surfaces.…”

“…Here, we generated magnetic fields following these four steps: an upward magnetic field (150 mT), a downward magnetic field (35 mT), a downward magnetic field (150 mT), and an upward magnetic field (35 mT) for the 1 st trap, 1 st release, 2 nd trap, and 2 nd release of magnetic nanobeads. The strengths of applied magnetic fields were determined to achieve an efficient trapping and a clean release during the repeated cycles [23]. The movement and distribution of magnetic beads were recorded by the fluorescence microscope.…”

Reusable surface plasmon resonance biosensor chip for the detection of H1N1 influenza virus

“…The uniformly controlled Ni patterns evenly deflect an applied external magnetic field. As a result, they can hold magnetic particles without a large aggregation (Yoo et al, 2016).…”

Staphylococcus aureus exotoxin detection using potentiometric nanobiosensor for microbial electrode approach with the effects of pH and temperature

“…The tube was cut vertically to reveal a small cross-section; a thin-layer membrane was then attached to the surface. [15,16] Preparation of a thin polymer membrane for the cross-section of the electrode First, 50 mg of polyvinyl chloride (PVC) powder, 50 mg of ionophore, and a specific amount of kaolinite-type pyrite cinder (KTPC) from the Iberian pyrite belt (IPB) were mixed with 75 mg of plasticizer. The resulting mixture was then dissolved in 5 mL of tetrahydrofuran in a 25-mm-thick glass beaker.…”

“…However, if the potential difference between two successive dilutions was less than 59 mV, then the sensor was not sensitive enough to detect the presence of exotoxin. [16] Reliability and lifetime of the sensor In this study, the sensor lifetime was determined by how long each MIP sensor could maintain its diagnostic properties. In addition, the sensors were also evaluated for their ability to detect the exotoxin within a given period.…”