Early
detection of immunoglobin G (IgG), a glycoprotein antibody
produced in the serum due to various infections, is of paramount importance
that will enable effective treatment, immunity assessment, and assist
in monitoring outbreaks of contagious diseases. This work demonstrates
the transverse magneto-optic Kerr effect (T-MOKE) based magnetoplasmons
excited on a composite ferromagnetic/plasmonic grating as a highly
sensitive, single wavelength, and target specific biosensing platform.
The sharp T-MOKE sensitivity curve corresponding to reduced fwhm results
in a two orders of magnitude enhancement in the resolving power compared
to conventional propagating surface plasmon polariton (SPP), which
is pivotal in identifying minute fluctuations in specific biomolecular
concentrations. An order of magnitude improvement in antibody immunoglobin
G (IgG) detection limit is observed compared to the SPP based sensing.
A detection limit down to 10 ng/mL (66 pM) is achieved using the proposed
T-MOKE technique. The results obtained provide compelling evidence
of the significantly superior sensitivity and resolving power of the
T-MOKE technique for the detection of Human IgG, and it is envisioned
that this spectroscopy free, single wavelength measurement approach
can be extended to detect biologically/chemically relevant molecules
at lower concentrations for early biomedical diagnosis and therapy.