Electrochemical aptasensor for ultrasensitive detection of PCB77 using thionine-functionalized MoS2-rGO nanohybrid

Endocrine disrupting chemicals in water and recent advances on their detection using electrochemical biosensors

“…Under faradaic EIS, visible differences can be observed in the Nyquist plot ranging from 2.92 × 10 −7 to 2.92 × 10 −3 ng mL −1 with a small standard deviation in each concentration, accompanied by an ultralow LOD of 9.344 × 10 −5 pg mL −1 . 151 Another aptamer-induced biosensing in virtue of thionine was performed by Mohammadi et al 152 with similar ultrasensitive outcomes. The selectivity test was carried out by introducing structural analogs of PCB 77 as well as heavy metal ions and the ratio of DPV responses after introducing interferants was highly close to that of the control group (i.e., PCB 77 only).…”

“…Some polymers containing amino groups such as poly (1,5-diaminonaphthalene) (P(1,5-DAN)) 129 and polyaniline (PANI), 132 can bind to antibodies through a direct and glutaraldehyde (GA)-linked interaction, respectively. AgNPs are capable of fixing thiol-terminated aptamers via the Ag-S bond, 132 while AuNPs have the ability to fix antigens, 130 thiolated aptamers 150,152,153 or complementary chains 149 via the Au-S bond. Moreover, Beiranvand et al 139 functionalized Fe 3 O 4 /AuNPs with amino groups to react with GA at first, leaving free aldehyde groups that were used to combine with non-thiolated aptamers.…”

“…Methylene blue (MB) 142,143,145,153,154,181,185 is the most familiar redox probe applied to electrochemical biosensing, along with others like toluidine blue (TB), 130 ferrocene (Fc), 146,150 thionine (Thi), 152 and biotin, 148 are also reported. Cetyltrimethylammonium bromide (CTAB) is a cationic surfactant, can either adsorb nanoparticles by virtue of electrostatic effects, 173 or preserve the activity of biological enzymes in the event of substrate reactions.…”

“…, PCB 77 only). 152 Han et al 145 constructed a special dendritic aptasensor used for the detection of PCB 72 in water. The aptamers were firstly allowed to grow on the skeleton of CaCO 3 particles loaded with MB.…”

“…Some studies have confirmed that the use of MoS 2 in combination with graphene can effectively improve the sensitivity of the detection platform. 112,152 As a novel planar material, MXene has been applied to support electrodes because of its large specific surface area, high electron mobility, and hydrophilic nature. 113,173 Electrode-supporting substances that contain functional ends are also frequently involved to present binding sites for biorecognition components.…”