Magnetron sputtering Si interlayer: A protocol to prepare solid phase microextraction coatings on metal-based fiber

Use of metal fibers in solid phase microextraction (SPME) can overcome the fragility drawback of conventional fused-silica ones. However, the surface modification of metal substrates is rather difficult, which largely prevents many mature traditional techniques, such as sol–gel and chemical bonding, being used in fabrication of SPME coating on metal-based fibers. This study demonstrates a protocol to resolve this problem by magnetron sputtering a firm Si interlayer on stainless steel fiber. The Si interlayer was easily modified active group, and attached with a multiwalled carbon nanotubes (MWCNTs) coating using the reported approach. The as-prepared MWCNTs/Si/stainless steel wire fiber not only preserved the excellent SPME behaviors of MWCNTs coatings, but also exhibited a number of advantages including high rigidity, long service life, and good stability at high temperature, in acid and alkali solutions. This new surface modification technique might provide a versatile approach to prepare sorbent coatings on unconfined substrates using traditional methods.