Detection of clinically relevant levels of protein analyte under physiologic buffer using planar field effect transistors

Gupta, Samit Kumar; Elias, Mark; Wen, Xuejin; Shapiro, John P.; Brillson, L. J.; Lu, Wu; Lee, Stephen Craig

doi:10.1016/j.bios.2008.05.011

Cited by 50 publications

(52 citation statements)

References 36 publications

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“…The next layer of interfaces used in our sensors (Shapiro et al 2007;Eteshola et al 2008;Gupta et al 2008) is provided by the reaction of sulpho-NHS-biotin with the silane polymer layer. Accordingly, each of the interfacial polymer layers used in figure 1 were reacted with sulpho-NHS-biotin and evaluated by AFM ( figure 5; table 1).…”

Section: Resultsmentioning

confidence: 99%

“…We use siloxane polymers to construct polymer layers to which analyte receptor proteins are affixed in our FET protein sensors (Bhushan et al , 2006aLee et al 2005;Shapiro et al 2007;Eteshola et al 2008;Gupta et al 2008). 3-APTES and 3-APDMES were purchased from Gelest (Morrisville, PA) and were used to construct polymer layers on metal Biomolecules on silane polymer surfaces B. Bhushan et al…”

Section: Reagentsmentioning

confidence: 99%

“…Multiple BioMEMS/NEMS protein sensors depend on proteins deployed on surfaces for their specific sensing properties, including fieldeffect transistor (FET) sensors (Shapiro et al 2007;Eteshola et al 2008;Gupta et al 2008), cantilever beam sensors (Lang et al 2005;Bhalerao et al 2007) and quantum dot sensors exploiting Forster resonance energy transfer (FRET; Fan et al 2005). When interfacial proteins are analyte receptors, loss of biomolecular function does not compromise the mechanical, electrical or quantum properties of the sensing transducers, but results in a loss of sensor biochemical specificity, causing sensor failure.…”

Section: Introductionmentioning

confidence: 99%

“…We are developing planar AlGaN/GaN heterojunction field-effect transistor sensors (HFETs; figure 1; Shapiro et al 2007;Gupta et al 2008) for clinically important protein analytes. We (Shapiro et al 2007;Gupta et al 2008) and others (Kang et al 2007) have shown that the classical dismissal of planar bioFETs for protein sensing in biological buffers/fluids (Bergveld 1991;Schoening & Poghossian 2002) is inappropriate.…”

Section: Introductionmentioning

confidence: 99%

“…We used 3-aminopropyltriethoxysilane (APTES) on MOSFET interfaces, and have also used APTES in functional HFET protein sensors (Bhushan et al , 2006a; Lee et al 2005;Shapiro et al 2007;Eteshola et al 2008;Gupta et al 2008). APTES layers are commonly described as self-assembled monolayers (SAMs), though this is often inaccurate (Kallury et al 1994; figure 2).…”

Section: Introductionmentioning

confidence: 99%

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Nanoscale adhesion, friction and wear studies of biomolecules on silane polymer-coated silica and alumina-based surfaces

Bhushan

Kwak

Gupta

et al. 2008

J. R. Soc. Interface.

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Proteins on biomicroelectromechanical systems (BioMEMS) confer specific molecular functionalities. In planar FET sensors (field-effect transistors, a class of devices whose protein-sensing capabilities we demonstrated in physiological buffers), interfacial proteins are analyte receptors, determining sensor molecular recognition specificity. Receptors are bound to the FET through a polymeric interface, and gross disruption of interfaces that removes a large percentage of receptors or inactivates large fractions of them diminishes sensor sensitivity. Sensitivity is also determined by the distance between the bound analyte and the semiconductor. Consequently, differential properties of surface polymers are design parameters for FET sensors. We compare thickness, surface roughness, adhesion, friction and wear properties of silane polymer layers bound to oxides (SiO 2 and Al 2 O 3 , as on AlGaN HFETs). We compare those properties of the film-substrate pairs after an additional deposition of biotin and streptavidin. Adhesion between protein and device and interfacial friction properties affect FET reliability because these parameters affect wear resistance of interfaces to abrasive insult in vivo. Adhesion/friction determines the extent of stickage between the interface and tissue and interfacial resistance to mechanical damage. We document systematic, consistent differences in thickness and wear resistance of silane films that can be correlated with film chemistry and deposition procedures, providing guidance for rational interfacial design for planar AlGaN HFET sensors.

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Section: Resultsmentioning

confidence: 99%