Analyzing the metabolites in single cells is important for several reasons:

1. Heterogeneity: Single cells within a population can exhibit significant heterogeneity in their metabolic profiles. Analyzing metabolites at the single-cell level allows for a more accurate understanding of this heterogeneity and its implications for cellular function and behavior.
2. Disease and drug response: Metabolic changes at the single-cell level can provide insights into disease progression and response to therapeutic interventions. Understanding the metabolic profiles of individual cells can help identify disease-specific metabolic signatures and potential targets for drug development.
3. Cellular function: Metabolites play a crucial role in regulating cellular function, including energy production, signaling, and biosynthesis. Analyzing metabolites at the single-cell level can provide valuable information about how individual cells regulate their metabolism to support specific functions.
4. Biomarker discovery: Single-cell metabolite analysis can lead to the discovery of novel biomarkers for various diseases and conditions. These biomarkers can be used for early detection, diagnosis, and monitoring of disease progression.
5. Systems biology: Integrating single-cell metabolite data with other omics data (such as genomics, transcriptomics, and proteomics) can provide a comprehensive understanding of cellular function and regulation within complex biological systems.

Overall, analyzing metabolites at the single-cell level is essential for gaining a deeper understanding of cellular metabolism, heterogeneity, and function, as well as for advancing personalized medicine and biomarker discovery.

But there are some challenges:

• Low picoliter volume of material available for analysis 
• Rapid metabolome shift because of stress
• Large diversity in metabolite structures, and concentrations
• Cell extraction
• Co-detection of isomeric and isobaric species
• High limits of detection due to low ionization efficiencies of some metabolites
• Quantification and identification
• Sample throughput

We are developing a novel ion source based on ultrasonic nebulization and dielectric barrier discharge to solve these problems.