Controlling carbon nanodot fluorescence for optical biosensing

Abstract

In this work we report on the optical properties of specific synthetic carbon nano-dots (CDs) and their suitability for the development of optical biosensors. We examine the photoluminescence behavior of these CDs under different conditions, in their native form, as well as when conjugated to the catalytic protein glucose oxidase (GOx) for the construction of optical glucose biosensors. The effect of pH and hydrogen peroxide on the observed spectra is examined as the basis for the biosensor development. The CDs examined here have inherent surface amino functional groups which allow for easy conjugation to biomolecules via EDC-NHS, providing a well defined platform for biosensing applications. We conclude that the well controlled, stable, and highly efficient fluorescence behavior of the CDs in solution or in conjugate, provides the grounds for this class of materials to be used in a variety of arrangements for the development of optical and optoelectrochemical detection systems.

Various responses of single-walled carbon nanotubes with differing chirality: A suggestion for biosensing

“…In the case of (10,5)/(8,7), the absorbance decreased in the presence of H 2 O 2 at all pH values and then recovered following the addition of catechin. A similar tendency was observed in (12,1)/(8,6), (9,4), and (10,2). Only (6,5) displayed different results.…”

“…The data clearly revealed different recovery ratios according to SWNT chirality, even at the same pH. For example, the absorbance recovery ratios at pH 6.0 were 1.67, 1.26, 1.26, 1.05, 1.02, and 0.98 in (10,5)/(8,7), (12,1)/(8,6), (9,4), (10,2), (7,5), and (6,5), respectively. The order of the values was not affected by pH.…”

“…The unique optical responses of carbon nanotubes (CNTs) have been intensively studied. [1][2][3][4] In particular, biological applications that use optical responses, such as DNA sensors and drug delivery systems, have been a focus of research. [5][6][7][8][9][10] Near infrared absorbance spectroscopy and near infrared photoluminescence spectroscopy are powerful tools for research, because the near infrared spectra of CNTs sensitively reflect the adsorption of molecules on the CNT surfaces.…”

Tumor-selective catalytic nanomedicine by nanocatalyst delivery

“…1a . GOD, (size: 6.0 nm × 5.2 nm × 7.7 nm) 24 and synthetic ultrasmall Fe 3 O 4 NPs (size: 2 nm) 25 , 26 were successively integrated into the large mesopores (~40 nm) of dendritic MSN (DMSNs) 27 to form a composite nanocatalyst for sequential catalytic reactions directly within the tumor tissue, designated as GOD-Fe 3 O 4 @DMSNs nanocatalysts (GFD NCs). Such a sequential nanocatalyst features high biocompatibility because the DMSNs supports, GOD and Fe 3 O 4 NPs are highly chemically compatible with each other, guaranteeing their biosafety in in vivo applications for catalytic tumor therapy.…”

Highly Sensitive Biosensors Based on Biomolecules and Functional Nanomaterials Depending on the Types of Nanomaterials: A Perspective Review

“…The application of carbon-based nanomaterials to develop biosensors received huge attention because of their advantages, such as a large surface-to-volume ratio and good chemical stability and biocompatibility [51,52]. For instance, carbon nanotubes (CNTs), carbon nanodots (CNDs), and graphene are the most widely known and used carbon-based nanomaterials [53][54][55], which are suitable for biological application due to their biocompatibility and high conductivity. In particular, CNDs are considered to be candidates for developing fluorescence and electrochemical biosensors due to their unique optical and electrochemical properties [56,57].…”