Retraction notice to "Optical sensing composites for cysteine detection: Combining rhodamine-based chemosensors with up-conversion nanocrystals" [Sens. Actuators B: Chem 238 (2017) 1293–1301]

Polymer–Graphene Nanocomposite Materials for Electrochemical Biosensing

“…[ 56 ] Depending on the SG/PPy composition and composite synthesis method, it is possible to obtain materials with electrical conductivities of up to 50 S cm −1 . Qian et al describe very promising PPy/rGO composites, decorated with AuNPs, [ 57 ] produced via in situ chemical oxidative polymerization on the surface of GO, utilizing HAuCl 4 , and followed reduction with hydrazine ( Figure 6 ). The resultant nanocomposite was tested for dopamine biosensing, combining impressive sensitivity (≈15 μA μ M −1 ), a low detection limit (≈20 × 10 −12 M ), and a linear range up to 5 × 10 −6 M , while resisting interference from uric acid and ascorbic acid.…”

“…Reprinted with permission. [ 57 ] Copyright 2014, Elsevier. (100 × 10 −15 M in serum) and the ability to discriminate even single base mismatches.…”