Microdroplets drive small-molecule activation reactions that are difficult in bulk solution. Recent studies have demonstrated that microdroplets activate inert N2 under ambient conditions to generate multiple nitrogencontaining compounds. However, there are still many controversial issues regarding the transformation of nitrogencontaining compounds in water microdroplets. Here, we combine online high-resolution mass spectrometry on two instrument platforms with 15N and 18O labeling to investigate nitrogen-containing species in pneumatically generated water microdroplets. Ammonium-containing water clusters, nitrite, and nitrate ions were detected on both instruments, whereas a signal assigned to NO+ was observed only on the Agilent 6224 TOF MS. Nebulization with

AbstractIn living cells, the conversion of squalene to lanosterol requires two dedicated enzymes and proceeds through 2,3-oxidosqualene as an essential intermediate. We show that water microdroplets contacting immiscible organic solvents accomplish this same multistep transformation without enzymatic catalysis. We propose that the oriented electric field across the water–organic interface generates reactive oxygen species that epoxidize squalene and then initiates acid-catalyzed ring-opening of the epoxide followed by a cationic polyene cyclization cascade to yield lanosterol. H218O labeling traced oxygen from water into TEMPO-derived and peroxyacetate ions observed by real-time mass spectrometry. LC–HRMS/MS further revealed C18–C30 reaction products with spectral matches to oxygenated terpenoid and steroid-like structures. We find that ethyl acetate is the most effective organic solvent because it generates peroxyacetic acid at the interface. Simulations show that a preformed protonated 2,3-oxidosqualene model remains hydrated and oriented after placement at the ethyl acetate–water interface, and calculations on microsolvation models indicate that an interfacial water configuration preferentially stabilizes the epoxidation transition state relative to the reactant by approximately 3 kcal mol–1. These results establish a plausible, abiotic pathway for steroid emergence and diversification at water–organic interfaces.

A digital microfluidic platform that integrates machine vision and AI-driven feedback transforms conventional colorimetric assays into autonomous, adaptive sensing systems for scalable biochemical ana...

A digital microfluidic platform that integrates machine vision and AI-driven feedback transforms conventional colorimetric assays into autonomous, adaptive sensing systems for scalable biochemical analysis.

European Journal of Mass Spectrometry, Ahead of Print. The accelerated condensation of a range of 4-substituted-1,2-phenylenediamines [YC6H3(NH2)2; Y = F, Cl, Br, CH3, CH3O, CN, CF3, CO2CH3or NO2] and 4,5-disubstituted-1,2-phenylenediamines [Y2C6H2(NH2)2; Y = F, Cl, Br or CH3] with 3,3’- and 4,4’-...

ABSTRACT Rationale Monomeric amino acids substitute into the ionized serine octamer (Ser8), a magic number cluster that exhibits chiral behavior. Small biomolecules, such as amino acids (AA), substitute into the octamer enantioselectively, giving Ser7AAH+ and Ser6AA2H+ favoring clusters of all L- or all D-chirality. While the formation of Ser8H+ has been well studied, its substitution reactions need further investigation. The fact that water microdroplets readily produce Ser8H+, which undergoes enantiospecific substitution reactions perhaps gives this topic relevance to origins of life chemistry. Methods The substitution reactions of several proteogenic AA's (Ala, Leu, isoLeu, Pro, Phe, and Val), along with prebiotically relevant isomers (norVal and isoVal), were investigated using a quadrupole ion trap mass spectrometer to gain insight into the determinants of the chiral behavior. Rather than using isotopically labeled enantiomers, as in previous work, cluster formation was assessed using samples of variable chiral composition and concentration. Results Substitution enantioselectivity was confirmed, though in the case of some double substitutions and the substitution of nonproteogenic isomers, the homochiral preference was decreased or inverted, an observation which is attributed to the disruption of the highly ordered noncovalent contacts of the parent Ser8 cluster. Additionally, the data suggest that octamer formation is consecutive: Ser8H+ forms first, followed by substitution of AA to form Ser7AAH+, sometimes followed by a second substitution to form Ser6AA2H+. Conclusions This investigation illustrates how chiral chemistry using MS must operate through weak but chirality-sensitive forces while avoiding dominance of stronger but chirality-insensitive reaction drivers; namely the propensity of a chiral organic base to acquire the charge of a proton affiliated with other chiral molecules. These results are significant because chiral molecular clusters are fundamentally interesting. Understanding the origins of their enantioselectivity contributes to a general understanding of how small molecules may recognize chirality in reaction partners and accumulate enantiomeric excess.

AbstractBulk nanobubbles (NBs) are metastable gas-filled voids in solution, with diameters of nearly 200 nm that exhibit long lifetimes and large surface-to-volume ratios. Recent studies have shown that chemical reactions are significantly accelerated within sprayed microdroplets during electrospray ionization mass spectrometry (ESI-MS). Although several factors, such as partial solvation of reagents, electric fields, ordered orientation, and pH, have been implicated in the acceleration in microdroplets, the primary governing factor remains unclear and dependent on the system. Similar processes occur on the nanobubble–liquid interface, leading to enhanced reaction rates when they are present in bulk solution. We demonstrate reaction rate acceleration by deliberately adding NBs to the bulk solution and microdroplets by considering two model systems: the Katritzky transamination reaction and the reaction between CO2 and N,N-dibutyl-1,3-propane diamine (DBPA). N2 and CO2 nanobubbles were generated using sonication, pressure cycling (PC), or the Tesla valve (TV) and delivered as bulk or spray solvents. The Katritzky reaction in bulk solution with NB-enriched solvent systems was examined by mass spectrometry under nonaccelerating electrospray conditions. The acceleration factor (AF) for the reaction doubled compared with the control. On the other hand, the microdroplet accelerated the Katritzky reaction, with N2 NB producing a further six-fold acceleration compared to the microdroplet control. For the reaction of the diamine DBPA with N2 nebulization, CO2 reagent delivery by NB resulted in acceleration factors between 2 and 50 compared to the microdroplet reaction control, depending on the solvent fraction, wherein bubbles were generated. With CO2, nebulization where ample reagent is already present, the addition of NBs produced a further two-to-five-fold acceleration factor depending on the solvent fraction in which NBs were generated, indicating a NB catalytic effect. Our findings show that NBs improve reaction kinetics by acting both as improved reagent delivery vehicles and/or as catalysts. Catalytic activity is a consequence of increased liquid–air interfacial surface area and improved reagent transport in bulk solution and within microdroplets.

2Pure Products has launched the game-changing OdorBac Air, an air-freshening system which destroys odours on contact, prevents them from returning and keeps areas fresh. “OdorBac Air’s odour‑neutralising technology works at a molecular level, eliminating malodours and delivering freshness without masking,” says 2Pure Products Director James Law. “The unique OdorBac Air odour removing solution is transformed into microdroplets and is projected into the atmosphere using specially developed air care dispensing systems that are designed for use in different areas of a building. “The technology attracts odour molecules into microdroplets and traps them. Specially formulated odour-destructive reagents within the patented formula then attack the odour compound on a molecular level. This instantly changes the molecular structure of the odour, so it is no longer an odour.” OdorBac Air systems are available in a variety of dispensing models designed for use in different locations, depending on requirements. Available in 1 litre refill bottles, OdorBac Air oils deliver consistent and memorable fragrance. Options including Midnight Amber, Vanilla Ember, Pure Linen and Seraphine – keeping areas fresh and offering consistent odour‑neutralising performance to suit different environments. https://2pureproducts.com The post Pure Products Launches Game-Changing OdorBac Air first appeared on Luxury Hospitality Magazine.

Researchers at the University of Illinois Urbana-Champaign have developed a fast, simple way to turn lignin, a plentiful plant-based byproduct of the papermaking industry, into potentially more valuable renewable chemicals.

Scientists from Nanyang Technological University, Singapore (NTU Singapore) have developed microscopic peptide droplets that deliver large amounts of gene-silencing molecules into cancer and immune cells, reducing the growth of hard-to-treat colorectal tumors by about 67% in mice.

Ultrasound-generated water microdroplets convert 56% of lignin waste into a potentially useful chemical in 20 minutes, without catalysts or harsh conditions.

Scientists from Nanyang Technological University, Singapore (NTU Singapore) have developed microscopic peptide droplets that deliver large amounts of gene-silencing molecules into cancer and immune cells, reducing the growth of hard-to-treat colorectal tumors by about 67% in mice. The patent-pending system uses small interfering RNA, or siRNA, to disrupt the production of two proteins that cancer cells exploit to evade attacks by the immune system.

Discontinuous dewetting on patterned surfaces enables microdroplet generation, yet predicting the resulting droplet heights has remained challenging. Wang et al. reveal that the pinning force and meniscus breakup, rather than viscous force alone, govern droplet heights, reconciling long-standing discrepancies between theory and experiment across diverse conditions.