Simultaneous Identification of Vitamins B1, B3, B5, and B6 by an Engineered Nanopore

Vitamin Bs, a group of water-soluble compounds, are essential nutrients for almost all living organisms. However, due to their structural heterogeneity, rapid and simultaneous analysis of multiple vitamin Bs is still challenging. In this paper, it is discovered that a hetero-octameric <i>Mycobacterium smegmatis</i> porin A (MspA) nanopore containing a sole nickel ion-bound nitrilotriacetic acid (NTA-Ni) adapter at its pore constriction is suitable for the simultaneous sensing of different vitamin Bs, including vitamin B1 (thiamine), vitamin B3 (nicotinic acid and nicotinamide), vitamin B5 (pantothenic acid), and vitamin B6 (pyridoxine, pyridoxal, and pyridoxamine). Assisted by a custom machine learning algorithm, all seven vitamin Bs can be fully distinguished, reporting a general accuracy of 99.9%. This method was further validated in the rapid analysis of commercial cosmetics and natural food, suggesting its potential uses in food and drug administration.