Antibody-free detection of amyloid beta peptides biomarkers in cerebrospinal fluid using capillary isotachophoresis coupled with mass spectrometry

Recent Electrokinetic and Microfluidic Strategies for Detection of Amyloid Beta Peptide Biomarkers: Towards Molecular Diagnosis of Alzheimer's Disease

“…In this novel technique, a sample containing Aβ 1 ‐ 40 was repeatedly injected and stacked by ITP for preconcentration for several cycles, allowing for the first time quantification limit down to 50 nM with UV detection [49] . ITP was then coupled with MS to preconcentrate a mixture of Aβ 1‐40, Aβ 1‐42, Aβ 1‐38 [50] . Separation of these peptides in this case was implemented by MS via their different mass‐to‐charge ratios.…”

“…Separation of these peptides in this case was implemented by MS via their different mass‐to‐charge ratios. The significant difference in Aβ 1–42/Aβ 1–40 ratio between AD patients and healthy volunteers was demonstrated [50] . Inspired from the ‘multi‐preconcentration concept’, we then went further with the development of a new mode named ‘multiple cycles of large volume sample stacking with electro‐osmotic pump’ (M–LVSEP) [51] .…”

“…1 nM Monitoring of the interaction between nanoparticles and the Aβ peptides [42][43][44][45][46] CE-LIF [41] Immunoprecipitation and off-line labelling Aβ1-42/Aβ1-38 0.1 nM Discrimination between AD patients and healthy persons [41] CE-LIF [47] Immuno-enrichmenton-bead fluorescent labelling -thermal elution Aβ1-42, Aβ1-40, Aβ1-38 0.1 nM Discrimination between AD patients and healthy persons [47] ITP-UV [48] -Aβ1-40 700 nM -Multiple-ITP-UV [49] -Aβ1-40 50 nM -ITP-MS [50] Off-line fluorescent labelling of peptides Aβ1-40, Aβ1-42, Aβ1-38 0.1 nM Discrimination between AD patients and healthy persons [50] Multiple LVSEP-LIF [51] Off-line fluorescent labelling of peptides [51] MCE-UV [52] - Biosensors [54,55] Sandwich immunoassay Aβ 1-42 0.5 μM Proof of concept Immuno-enrichment on magnetic beads prior to CE-UV [60] -Aβ 1-42 and Aβ 1-40 sub μM range -Immuno-enrichment on magnetic beads and fluorescent labelling prior to CE-LIF [41,52,[61][62][63]47] -Aβ 1-38, Aβ 1-40, and Aβ 1-42 sub nM ranges Discrimination between AD patients and healthy persons [41,52,[61][62][63]47] Immunoassay in microfluidic droplets [57] Single-step immunoassay using functionalized magnetic beads Magneto-CE [59] Immuno-capture and chemical elution of labelled peptides inside a CE microchannel peptides in biofluids in particular. The first CE method for separation and ultraviolet (UV) detection of Aβ peptides was communicated in 2008.…”

“…[49] ITP was then coupled with MS to preconcentrate a mixture of Aβ 1-40, Aβ 1-42, Aβ 1-38 . [50] Separation of these peptides in this case was implemented by MS via their different mass-tocharge ratios. The significant difference in Aβ 1-42/Aβ 1-40 .…”

“…2021, 21, 149 -161 ratio between AD patients and healthy volunteers was demonstrated. [50] Inspired from the 'multi-preconcentration concept', we then went further with the development of a new mode named 'multiple cycles of large volume sample stacking with electro-osmotic pump' (M-LVSEP). [51] In this method (see Figure 4A for working principle), an Aβ peptide mixture was injected into the whole CE capillary and was swept back to the capillary inlet by the bulk liquid flow (EOF) for preconcentration.…”