Nanopore Identification of Alditol Epimers and Their Application in Rapid Analysis of Alditol-Containing Drinks and Healthcare Products

Abstract

Alditols, which have a sweet taste but produce much lower calories than natural sugars, are widely used as artificial sweeteners. Alditols are the reduced forms of monosaccharide aldoses, and different alditols are diastereomers or epimers of each other and direct and rapid identification by conventional methods is difficult. Nanopores, which are emerging single-molecule sensors with exceptional resolution when engineered appropriately, are useful for the recognition of diastereomers and epimers. In this work, direct distinguishing of alditols corresponding to all 15 monosaccharide aldoses was achieved by a boronic acid-appended hetero-octameric Mycobacterium smegmatis porin A (MspA) nanopore (MspA-PBA). Thirteen alditols including glycerol, erythritol, threitol, adonitol, arabitol, xylitol, mannitol, sorbitol, allitol, dulcitol, iditol, talitol, and gulitol (l-sorbitol) could be fully distinguished, and their sensing features constitute a complete nanopore alditol database. To automate event classification, a custom machine-learning algorithm was developed and delivered a 99.9% validation accuracy. This strategy was also used to identify alditol components in commercially available “zero-sugar” drinks and healthcare products, suggesting their use in rapid and sensitive quality control for the food and medical industry.

Discrimination of Ribonucleoside Mono-, Di-, and Triphosphates Using an Engineered Nanopore

“…The preparation of (N90C) 1 (M2) 7 was performed as reported. − Experimentally, the E. coli BL21 (DE3) pLysS containing the recombinant plasmids was first spread on an LB agar plate containing ampicillin (50 μg/mL) and chloramphenicol (34 μg/mL).…”

“…For simplicity, this highly engineered hetero-octameric pore assembly is referred to as MspA-PBA. − Acknowledging the high resolution of MspA, it successfully achieved direct discrimination among monosaccharides, nucleoside monophosphates and their epigenetic modifications, and all alditols . Assisted by custom machine-learning models, the overall sensing accuracies were respectively evaluated to be 96.0%, 99.6%, and 99.9%, suggesting a superior performance of MspA-PBA on small-molecule sensing. In nature, ribonucleotides could simultaneously exist in the form of ribonucleoside mono-, di-, and triphosphates .…”

“…Experimentally, a hetero-octameric MspA was first prepared and then further conjugated with a sole PBA adapter at its pore constriction. For simplicity, this highly engineered hetero-octameric pore assembly is referred to as MspA-PBA. − Acknowledging the high resolution of MspA, it successfully achieved direct discrimination among monosaccharides, nucleoside monophosphates and their epigenetic modifications, and all alditols . Assisted by custom machine-learning models, the overall sensing accuracies were respectively evaluated to be 96.0%, 99.6%, and 99.9%, suggesting a superior performance of MspA-PBA on small-molecule sensing.…”

Single-Molecule Interconversion between Chiral Configurations of Boronate Esters Observed in a Nanoreactor

“…Boronic acids have been previously applied as adapters of an α-HL or an MspA − nanoreactor and used for the detection of saccharides, alditols, and nucleotides. However, none of these projects focused on the chiral configurational interconversion of boronate esters.…”

Detection of Tobacco Bacterial Wilt Caused by Ralstonia solanacearum by Combining Polymerase Chain Reaction with an α-Hemolysin Nanopore

“…In general, the size of the channel diameter is the dominant factor that affects the distinguishing ability and application scope of the nanopore. Herein, α-hemolysin (α-HL), a well-studied bacterial-derived toxin with the narrowest constriction of 1.4 nm [ 26 , 27 , 28 , 29 ], was utilized for analysis. A single-stranded DNA (ssDNA) with 198 nucleotides was obtained via asymmetric PCR or the lambda exonuclease-mediated degradation of the PCR product.…”