title: Using membrane composition to fine-tune the pKaof an optical liposome pH sensor.
abstract: Liposomes containing membrane-anchored pH-sensitive optical probes are valuable sensors for monitoring pH in various biomedical samples. The dynamic range of the sensor is maximized when the probe pKais close to the expected sample pH. While some biomedical samples are close to neutral pH there are several circumstances where the pH is 1 or 2 units lower. Thus, there is a need to fine-tune the probe pKain a predictable way. This investigation examined two lipid-conjugated optical probes, each with appended deep-red cyanine dyes containing indoline nitrogen atoms that are protonated in acid. The presence of anionic phospholipids in the liposomes stabilized the protonated probes and increased the probe pKavalues by < 1 unit. The results show that rational modification of the membrane composition is a general non-covalent way to fine-tune the pKaof an optical liposome sensor for optimal pH sensing performance.
authors.affiliation: Department of Chemistry and Biochemistry, 236 Nieuwland Science Hall, University of Notre Dame, Notre Dame, Indiana 46556, United States.
authors.forename: Kasey J
authors.initials: KJ
authors.lastname: Clear
authors.affiliation: Department of Chemistry and Biochemistry, 236 Nieuwland Science Hall, University of Notre Dame, Notre Dame, Indiana 46556, United States.
authors.forename: Katelyn
authors.initials: K
authors.lastname: Virga
authors.affiliation: Department of Chemistry and Biochemistry, 236 Nieuwland Science Hall, University of Notre Dame, Notre Dame, Indiana 46556, United States.
authors.forename: Lawrence
authors.initials: L
authors.lastname: Gray
authors.affiliation: Department of Chemistry and Biochemistry, 236 Nieuwland Science Hall, University of Notre Dame, Notre Dame, Indiana 46556, United States.
authors.forename: Bradley D
authors.initials: BD
authors.lastname: Smith