Single-Walled Carbon Nanohorns as Boosting Surface for the Analysis of Low-Molecular-Weight Compounds by SALDI-MS

Abstract

Limits of Matrix-Assisted Laser Desorption Ionization (MALDI) mass spectrometry (MS) in the study of small molecules are due to matrix-related interfering species in the low m/z range. Single-walled carbon nanohorns (SWCNH) were here evaluated as a specific surface for the rapid analysis of amino acids and lipids by Surface-Assisted Laser Desorption Ionization (SALDI). The method was optimized for detecting twenty amino acids, mainly present as cationized species, with the [M+K]+ response generally 2-time larger than the [M+Na]+ one. The [M+Na]+/[M+K]+ signals ratio was tentatively correlated with the molecular weight, dipole moment and binding affinity, to describe the amino acids’ coordination ability. The SWCNH-based surface was also tested for analyzing triglycerides in olive oil samples, showing promising results in determining the percentage composition of fatty acids without any sample treatment. Results indicated that SWCNH is a promising substrate for the SALDI-MS analysis of low molecular weight compounds with different polarities, enlarging the analytical platforms for MALDI applications.

Carbon-Based Nanoparticles and Their Surface-Modified Counterparts as MALDI Matrices

“…Single-walled carbon nanohorns, for example, have been proven to show salt tolerance up to a concentration of 10 mmol/L, a property that makes these matrices suitable for the analysis of complex biological samples. 185 Metal-based nanoparticles have a high ionization efficiency and chemical stability, similar to carbon-based nanoparticles. The production cost of metallic nanoparticles is, however, generally lower than that of carbon-based nanoparticles, a property that has contributed to their extensive use as MALDI matrices.…”

“…Shortly after the development of MALDI ionization, several researchers tested the possibility of using different nanoparticles as alternative matrices to conventional ones. − Carbon-based nanoparticles, silicon-based nanoparticles, metallic nanoparticles, and their combinations (i.e., hybrid matrices) are among the main groups of nanosized matrices. − In this paper, we reviewed in detail carbon-based matrices and their derivatives, and here we briefly compare other nanoparticles utilized as MALDI matrices to carbon-based ones.…”

“…As discussed in detail in the previous sections, a higher tolerance to salts has also been reported with many carbon-based nanoparticles. Single-walled carbon nanohorns, for example, have been proven to show salt tolerance up to a concentration of 10 mmol/L, a property that makes these matrices suitable for the analysis of complex biological samples . Metal-based nanoparticles have a high ionization efficiency and chemical stability, similar to carbon-based nanoparticles.…”

One-step electrodeposited hybrid nanofilms in amperometric biosensor development

“…11 The main functional sensitive element in biosensors is a hybrid organic–inorganic (OIH) layer. 12,13 OIH layers are self-organizing systems consisting of inorganic components (metal, semiconductor and, dielectric particles) and organic components (polymers, enzymes and, cofactors). 14 Regardless of the approach used for preparation, functional OIH films, type, structure and synthesis together determine the quality of the analytical signals of electrochemical biosensors.…”