Non‐Invasive Ammonia Detection on Cancer Cell Surfaces Using Liquid Crystal Elastomer

Abstract Delving into the intricate world of cancer cells requires a profound understanding of the signaling molecules released from the cells. In this contribution, ammonia (NH₃) is monitored, a small signaling molecule and potential cancer biomarker, on the cell surfaces through liquid crystal elastomer microspheres (LCEM) at the single‐cell level. The LCEM are synthesized from molecular building blocks, 7‐octenoic acid (7OAc) and 2‐methyl‐1,4‐phenylene bis(4‐((acryloyloxy)hexyl)oxy) benzoate (RM82) and adorned on the surfaces of healthy human umbilical vein endothelial cells (HUVEC), and cancerous, human primary glioblastoma (U87), human colon carcinoma (CaCo‐2), and human breast adenocarcinoma (MCF7) cells, cultured within microfluidic channels. The ethereal release of NH₃ from living cells is monitored through a radial‐to‐concentric transfiguration of LCEM. The cellular heterogeneity among cancerous cell populations is unraveled by mapping the LCEM morphology on 100 cells of each cell line. The LCEM paves the way for designing probes that offer selective, simplistic, and label‐free monitoring of the biochemical processes unfurling on the surfaces of living cells, which are challenging to measure through other analytical techniques.