Human IgG detection in serum on polymer based Mach-Zehnder interferometric biosensors

Abstract

We report a new method for detecting human IgG (hIgG) in serum on integrated-optical Mach-Zehnder interferometer biosensors realized in a high index contrast polymer material system. In the linear range of the sensor (5-200 nM) we observed excellent signal recoveries (95-110%) in buffer and serum samples, which indicate the absence of matrix effects. Signal enhancement was reached by using secondary anti-human IgG antibodies, which bind to immobilized target IgGs and allow detecting concentrations down to 100 pM. This polymer based optical sensor is fully compatible with cost-efficient mass production technologies, which makes it an attractive alternative to inorganic optical sensors. Graphical abstract of the hIgG measured on polymer based photonic sensors using a direct binding assay and a signal enhancement strategy with secondary antibodies.

Dielectric barrier discharge plasma treatment of modified SU-8 for biosensing applications

“…Several works based on polymeric technology for biosensing applications, do not show the biofunctionalization process directly on the polymer surface, in some cases the biofunctionalization is made on materials such as metal (nano-particles or nano-layer) preferably gold or silver as it was said in our manuscript, deposited on polymeric surface [23][24][25], in others cases, was used titanium dioxide (TiO 2 ) [27,28], tantalum pentoxide (Ta 2 O 5 ) [29,30] and in very specific cases some proteins [2]. It must be considered that the deposition of these additional materials, increase the production costs of the proposed device and decrease the performance of the projected components, because the generated evanescent wave is hindered by this type of procedure, specially in integrated photonics.…”

“…The SU-8 is an epoxy that has been widely used in the fabrication of optical telecommunication and biosensor devices [1][2][3]. The advantage of the implementation of this material is based on attributes such as high refractive index, mechanical and thermal stability, reliability, low loss and easy fabrication.…”

Progress of infrared guided-wave nanophotonic sensors and devices

“…Compared with the same structures working at 1550 nm, higher Q factors and lower iLoDs were observed. Melnik et al [67] demonstrated a polyimide-based MZI biosensor at a central wavelength of 1310 nm. Human IgG detection was performed, showing a surface sLoDs of 3.1 nM and 0.03 nM by label-free and labeled methods, respectively.…”

Label-Free Biosensors Based onto Monolithically Integrated onto Silicon Optical Transducers

“…Although the majority of integrated MZI sensors depend on devices fabricated on silicon materials, polymers have also been implemented due to their lower cost compared with silicon-based ones. Thus, a polyimide-based MZI modified with streptavidin to couple a biotinylated anti-human IgG antibody was applied for the determination of human IgG with an LOD of 3.1 nM for direct binding, which was reduced to 30 pM when a second anti-human IgG antibody was employed [102]. Considering the LODs achieved so far, polymer-based MZIs could evolve to low-cost, disposable immunosensors.…”