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Indexed by:期刊论文

Date of Publication:2018-11-10

Journal:SENSORS AND ACTUATORS B-CHEMICAL

Included Journals:SCIE、Scopus

Volume:273

Page Number:1508-1518

ISSN No.:0925-4005

Key Words:Selective-wettability modification; Polymer; UV/ozone; Microfluidic device

Abstract:Poly (methyl methacrylate) (PMMA) has become increasingly popular to fabricate microfluidic devices. In a microfluidic device, different functional areas usually require different wettability to achieve a better performance. However, most of the existing wettability modification methods have been applied to the whole PMMA surface making the device have minimum wettability difference. In this paper, a controllable gradient UV irradiation (CGUI) method was presented. In this method, a series of quartz plates sputtered with different thickness of Cu were arranged on top of the PMMA surface. By controlling the thickness of Cu film, the UV irradiation, which transmitted though the quartz plates onto the PMMA surface, can be adjusted making the modification performance able to be varied accordingly. The validation of the proposed CGUI was conducted through contact angle measurements. Our results showed that through 5 min CGUI process, the contact angle for different parts of the PMMA surface can be varied from 45.48 degrees to 77.41 degrees continuously with a long-term stability of 60 days. To demonstrate this method, a fully integrated Point-of-Care Test (POCT) device was designed and fabricated for the detection of cardiac Troponin I achieving the lower detection limit of 85 pg/ml within 10 min.