Tensor 2

Coupled thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) were conducted in a nitrogen atmosphere. A TGA STA F3 449 Jupiter from Netzsch (Selb, Germany) equipped with a high-speed furnace was used for the study. A steady heating rate of 20 K/min was used between 50 °C and 800 °C at a N2 flow rate of 70 mL/min. Due to high end temperatures, the sample carrier (TG-DSC) was equipped with aluminum oxide tilts. Sample weights were kept constant at 10 ± 1 mg (20 K/min). The onset temperature was defined as 99% residual mass. All tests were conducted three times, and averaged curves are presented. The FTIR unit Tensor 2 from Bruker Corp. (Billerica, Massachusetts, USA) was coupled by a 230 °C controlled transfer line. FTIR gas-cell temperatures were controlled at 200 °C; 32 scans were averaged. A 30 s measurement delay occurred between TGA and FTIR results, which corresponds to 10 °C.

2 mg of fucoidan and 200 mg of KBr were combined and pure KBr powder was used as blank. The samples were sufficiently mixed, compressed into tablets and placed in an FTIR spectrometer (BRUKER TENSOR-2, BRUKER, Germany) for scanning, with a scanning wavelength range of 400–4000 cm⁻¹.

The EVA/BCZT/Pt thin film is firstly transferred to a 20 nm thick Pt coated PDMS membrane with 200 μm. The EVA is removed by a small amount of toluene. A 2 mm diameter, 20 nm thick gold film is sputtered onto another 20 μm thick PDMS membrane to increase the signal strength and the gold deposited side is attached to the BCZT film for encapsulation. This device is clamped and fixed by two $3\text{cm}\times 4\text{cm}$ , 1 mm thick PCBs, with the upper and lower electrodes each directly touching the board conductor and integrated into a BNC connector. The resonant frequency is characterized by the ENA Network Analyzer (E5061B, Keysight).
Before starting the experiment, the PDMS surface needs to be grafted with carboxyl groups. Firstly, PDMS is immersed in benzophenone (10 wt% in water, TCI, > 99%) for 4 h, dried for 5 h thick with UV light for 5 min and soaked with ethanol. After drying, the surface is dripped with 50% aqueous acrylic solution and irradiated with UV light for 5 min. After drying, the surface is dripped with 50% aqueous acrylic solution and irradiated with UV light for 5 min, and the surface is cleaned with deionized water. The grafted results are characterized by FTIR (Tensor 2, Bruker). The antibodies with fluorescent labeling (SARS-CoV-2 Spike RBD HL1002) are purchased from GeneTax. The samples are imaged with a fluorescence microscope (Nikon, Eclipse Ci-L, Japan).

Fourier transform infrared (FTIR) spectroscopy (Bruker Tensor II) was performed on the materials in attenuated total reflection (ATR) configuration. The spectra were acquired accumulating 32 scans in 4000–600 cm⁻¹ range with resolution of 2 cm⁻¹.

Infrared spectra of the composites were recorded with a Fourier transform infrared spectrometer (FTIR, Tensor II, Bruker, Billica, MA, USA) between 4000 and 600 cm⁻¹. X-ray diffraction (XRD) analysis was conducted on a Bruker D8 Focus X-ray diffractometer by a solid detector and Cu Ka radiation. The 2θ ranges were from 5° to 40° at a rate of 5°/min.