BRASUEL, M, KOPELMAN, R, AYLOTT, JW, CLARK, H, XU, H, HOYER, M, MILLER, TJ, TJALKENS, R and PHILBERT, MA, 2002. Production, characteristics and applications of fluorescent PEBBLE nanosensors: Potassium, oxygen, calcium and pH imaging inside live cells SENSORS AND MATERIALS. 14(6), 309-338