Electrochemical Biosensing Using Amplification-by-Polymerization

Abstract

A novel signal amplification strategy for electrochemical detection of DNA and proteins based on the amplification-by-polymerization concept is described. Specifically, a controlled radical polymerization reaction is triggered after the capture of target molecules on the electrode surface. Growth of long chain polymeric materials provides numerous sites for subsequent aminoferrocene coupling, which in turn significantly enhances electrochemical signal output. Activators generated electron transfer for atom transfer radical polymerization (AGET ATRP) is used in this study for its high efficiency in polymer grafting and better tolerance toward oxygen in air. 2-Hydroxyethyl methacrylate (HEMA) and glycidyl methacrylate (GMA) are examined to provide excess hydroxyl or epoxy groups for aminoferrocene coupling. A limit of detection of 15 pM and 0.07 ng/mL is demonstrated for DNA and ovalbumin, respectively. More than 7-fold signal enhancement in ovalbumin detection has been achieved comparing to the unamplified method. In addition, a more than 5 orders of magnitude of dynamic range is achieved with a linear correlation coefficient (R(2)) of 0.997 for DNA, and a more than 3 orders of magnitude with R(2) of 0.999 for ovalbumin. Together, the results show that the coupling of amplification-by-polymerization concept with electrochemical detection offers great promises in providing a sensitive and cost-effective solution for biosensing applications.

Click Chemistry: A Powerful and Versatile Methodology for Preparation of Ferrocene-Containing Polymers

“…For example, Fc-based polymer brushes grafted on solid substrates have been employed for the development of electro-active and electro-catalytic films, electrochemical DNA sensors, and amperometric biosensors [50][51][52][53]. Fu et al reported a gold substrate with surface-grafted Fc-based polymer brushes (Au-g-PFTMA) (P24), which was prepared by combination of surface-initiated atom transfer radical polymerization (SI-ATRP) and CuAAC in one pot (Scheme 6) [54].…”

Study on the electrochemical, thermal, and liquid crystalline properties of poly(diethyleneglycol 1,1′-ferrocene dicarboxylate)

“…Ferrocene-based polymers have wide applications in different fields like optical display technologies [17], amperometric biosensors [18,19], DNA and protein sensors [20,21], carbon monoxide sensors, [22] and in the construction of optical logic gates [23]. Additionally, ferrocene-based photocross-linkable redox polymers have been synthesized for the design of enzyme-based sensors and fuel cells [24].…”

A novel sensitive immunoassay by nucleic acid barcode dot and its application in the detection of prostate-specific antigen

“…Polymerase chain reaction (PCR) technology has been used for the amplification and detection of trace amounts of DNA (5). This technology can theoretically detect single stranded DNA and has good specificity (6).…”