Comparison of anti-HER2 antibody immobilization using three different techniques on aluminum-aluminum nitride-aluminum thin films produced by radiofrequency sputtering

Figures & data

Table 1 Operational conditions for aluminum-aluminum nitride-aluminum thin film deposition

Condition	Al deposition	AlN deposition
Deposition pressure (Pa)	2.66	0.266
Argon flux (scc)	30	15
Nitrogen flux (scc)	0	15
Radiofrequency power (W)	50, 100, 150	150
Distance (cm)	6	6

Abbreviations: Al, aluminum; AlN, aluminum nitride; scc, standard cubic centimeter per minute.

Figure 1 Scanning electron microscopic images of the surfaces in the three different groups in the study.

Notes: (A) 584 nm, (B) 328 nm, and (C) 201 nm. Groups of slides with these surfaces were biofunctionalized with anti-HER2 antibodies using protein G, sodium alginate, or direct adsorption.

Figure 2 X-ray diffraction pattern of an aluminum-aluminum nitride-aluminum thin film layer on a silicon wafer. Cubic AlN (111) emission.

Abbreviations: AlN, aluminum nitride; XRD, X-ray diffraction.

Figure 3 Box plot of concentration of HER2 detected on the surfaces of aluminum-aluminum nitride-aluminum thin films, by different immobilization protocols, regardless of grain size.

Note: (A) Sodium alginate, (D) direct immobilization, (G12) 12 hours incubating protein G, and (G2) 2 hours incubating protein G.

Table 2 Average detected HER2 concentration per group

	Average ± SD concentration	Normalized with direct immobilization	Normalized with alginate
Alginate	6.054±2.1	2.689	1
Direct	2.251±0.5	1.000	0.371
G12h	16.443±6.7	7.302	2.716
G2h	8.197±2.4	3.640	1.353

Note: The above values are standardized readings.

Abbreviations: SD, standard deviation; G12h, 12 hours incubating protein G; G2h, 2 hours incubating protein G.

Figure 4 Box plot of the concentration of HER2 detected on the surfaces of aluminum-aluminum nitride-aluminum thin films, by different immobilization protocols, depending on the grain size of the surface.

Note: (A) Sodium alginate, (D) direct immobilization, (G12) 12 hours incubating protein G, and (G2) 2 hours incubating protein G.
Abbreviations: L, large; M, medium; S, small; A, alginate immobilization; D, direct immobilization; G12, protein G 12 hours; G2, protein G 2 hours.