Two Orders of Magnitude Boost in the Detection Limit of Droplet-Based Micro-Magnetofluidics with Planar Hall Effect Sensors

被引：5

作者：

Schuett, Julian ^{[1
]}

Thing, Rico ^{[1
]}

Volkov, Oleksii ^{[1
]}

Kosub, Tobias ^{[1
]}

Nicolas, Pablo ^{[1
,2
,3
]}

Nhalil, Granell Hariharan ^{[4
,5
]}

Fassbender, Jurgen ^{[1
]}

Klein, Lior ^{[4
,5
]}

Grosz, Asaf ^{[6
]}

Makarov, Denys ^{[1
]}

机构：

[1] Helmholtz Zentrum Dresden Rossendoif eV, Inst Ion Beam Phys & Mat Res, D-01328 Dresden, Germany

[2] UNSAM, Escuela Ciencia & Tecnol, B1650KNA, Buenos Aires, DF, Argentina

[3] Inst Nacl Tecnol Ind, B1650KNA, Buenos Aires, DF, Argentina

[4] Bar Ilan Univ, Dept Phys, IL-5290002 Ramat Gan, Israel

[5] Bar Ilan Univ, Inst Nanotechnol & Adv Mat, IL-5290002 Ramat Gan, Israel

[6] Ben Gurion Univ Negev, Dept Elect & Comp Engn, IL-84105 Beer Sheva, Israel

来源：

ACS OMEGA | 2020年 / 5卷 / 32期

关键词：

MAGNETIC NANOPARTICLES; ULTRASENSITIVE DETECTION; PLATFORM; CAPTURE; SAMPLES; FIELD; SIZE;

D O I：

10.1021/acsomega.0c02892

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Magnetofluidics is a dynamic research field, which requires novel sensor solutions to boost the detection limit of tiny quantities of magnetized objects. Here, we present a sensing strategy relying on planar Hall effect sensors in droplet-based micro-magnetofluidics for the detection of a multiphase liquid flow, i.e., superparamagnetic aqueous droplets in an oil carrier phase. The high resolution of the sensor allows the detection of nanoliter-sized superparamagnetic droplets with a concentration of 0.58 mg/cm(3), even when they are biased in a geomagnetic field only The limit of detection can be boosted another order of magnitude, reaching 0.04 mg/cm(3) (1.4 million particles in a single 100 nL droplet) when a magnetic field of 5 mT is applied to bias the droplets. With this performance, our sensing platform outperforms the state-of-the-art solutions in droplet-based micro-magnetofluidics by a factor of 100. This allows us to detect ferrofluid droplets in clinically and biologically relevant concentrations and even below without the need of externally applied magnetic fields. These results open the route for ferrofluids in microfluidic geometries in, e.g., bio(-chemical) or medical applications.

引用

页码：20609 / 20617

页数：9