Pathogen Detection Using Magnetoelastic Biosentinels - Biomedical Engineering Systems and Technologies - page 47

Pathogen Detection Using Magnetoelastic Biosentinels

Howard Clyde Wikle, III , Suiqiong Li, Aleksandr Simonian, and Bryan A. Chin

Materials Research & Education Center, Auburn University, Auburn, AL, U.S.A.
{hcw0002,lisuiqi,simonal,chinbry}@auburn.edu

Abstract. Biosentinels, used to detect, signal, and capture pathogenic bacteria,
are discussed. The biosentinel is based on magnetically soft magnetoelastic re-
sonators coated with a selective and specific biorecognition layer. The biosenti-
nels are actuated, monitored, and controlled wirelessly by external magnetic
fields. The biosentinels mimic the function of naturally occurring biological de-
fensive systems, such as white blood cells, seeking out and capturing pathogen-
ic bacteria. After binding with the target pathogen, the mass of the biosentinel
increases causing the resonant frequency to decrease, providing instantaneous
detection of the pathogen. The biosentinels require no on-board power, harvest-
ing electromagnetic energy from the surroundings for propulsion, navigation,
and signaling the detection of target pathogens.

Keywords: Pathogen detection, Biosensor, Bio-inspired, Phage, Magnetoelastic,
Wireless sensor.

1 Introduction

For centuries, humankind has attempted to mimic the designs of Nature to develop
new engineering materials and systems. The human blood system is an excellent ex-
ample of one of Nature's amazing creations that inspires us in this work. The human
blood contains many components that work synergistically to keep us healthy. As part
of the immune system, white blood cells are the main defensive mechanism against
pathogenic invaders. There are a variety of white blood cell types (neutrophil, eosino-
phil, lymphocytes, etc.) that target different pathogens. This capability serves as the
model for a bio-inspired system of autonomous sentinels for the capture and detection
of invasive pathogens. To provide proof-in-principal, research results for bacterial
detection using magnetoelastic biosentinels in liquid analytes are presented. Potential
short term applications include the capture and detection of bacteria in urine and
li-quid food products such as water, juices and milk. A variety of sentinels, similar to
different types of white blood cells, may be constructed to target different bacterial
pathogens (Figure 1). The envisioned sentinels will autonomously move through a
liquid, seeking out and capturing specific invading bacterial pathogens. A sentinel is
constructed of a freestanding magnetoelastic (ME) resonator (transducer platform)
that is coated with a biorecognition layer (bacteriophage) that specifically captures or
binds a single type of pathogen.