Table 3: Summary of sensing performance of metal functionalized CNT sensors. (Note: N/S = Not-stated.)

MetalCNT typeSensor configurationTargeted analytesDetection limitResponse timeRecovery timeReference

PdS-SWCNTFET H2 40 ppm 5–10 s (for half resistance change)400 s[49]
PdSWCNTsResistorH21000 ppmN/SN/S [50]
PdSWCNTsResistorH2100 ppm10 min20 min[51]
PdSWCNTsResistorH2100 ppm 3–60 s (for 36.8% resistance change) 5 min [52]
PdSWCNTsResistorH2 10 ppm 10 min 30 s[53]
PdACNTsResistorH2100 ppm 7 minN/S[54]
PdSWCNTsResistorCH46 ppm 2–4 minN/S[55]
PdMWCNTsResistorCH42% 310 s 176 s[56]
Pt MWCNTsResistorH2N/S10 min15 min[57]
PdMWCNTsResistorH2N/S7 min7 min[58]
Pt MWCNTsResistorH2, NO2, H2ON/S 10 min 14 min[59]
AuSWCNTsResistorNH3, NO2 120 ppb NH3150 s200 s[60]
Au, PtMWCNTsResistorNO2, NH3100 ppb NO2, 5 ppm NH3N/SN/S [61]
Au, AgMWCNTsResistorNO2500 ppb NO2 20 minN/S[62]
Pt, Pd, Sn, RhSWCNTsFETH2, CH4, CO, H2SN/S 5 minN/S[63]
Pd, AuSWCNTsResistorNO2, HCN, HCl, Cl2, acetone, benzene5 ppmN/SN/S[64]