Multiple MoS2 Transistors for Sensing Molecule ... - Semantic Scholar
Multiple MoS2 Transistors for Sensing Molecule Interaction Kinetics
Hongsuk Nam1, †, Bo-Ram Oh1, †, Pengyu Chen1, Mikai Chen1, Sungjin Wi1, Wenjie Wan2, Katsuo Kurabayashi1, and Xiaogan Liang*,1 1 2
Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109
University of Michigan-Shanghai Jiao Tong University Joint Institute and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
*Contact Email: [email protected] †
These authors contributed equally
Supporting Information
1
Figure S1. S Protoco ol for functiionalizing a MoS2 trannsistor senssor with antti-human TN NF-α antibody receptors fo or detecting TNF-α moleecules: (1) Im mmerse the HfO2-coatedd MoS2 transistor sensor in nto a 5% AP PTES solutio on and incub bate for 1 hoour. (2) Thee HfO2 surfaace silanizedd with APTES reacts r with a 5% solution n of glutaralldehyde (GA A) in phosphhate bufferedd saline (PBS S) for 2 hours, followed by y rinsing with PBS bufffer. (3) The HfO2 surface is then inncubated wiith an man TNF-α antibody a solution for 1 hour. (4) Thhe as-functiionalized sennsor is incubbated anti-hum with TN NF-α solution ns with inccremental co oncentrationns (2 hours for each cooncentrationn) for studying the sensor responses r att the equilib brium state aand the affinnity of the aantibody-(TN NF-α) pair, or the t device is subjected to a TNF-α α flow in a m microfluidicc channel forr quantifyinng the time-dependent assocciation/disso ociation kineetics of the anntibody-(TN NF-α) pair.
2
Figure S2. S The dual-gate thin-film transistorr biosensor m model: The binding of T TNF-α moleecules with the antibody reeceptors fun nctionalized on the HfO O2 effective layer can ccause a poteential change (Δ ΔΦ) on thiss effective laayer. ΔΦ caan be evaluaated using
qN TNF , where q iis the C HfO 2
effective charge brou ught to the HfO H 2 effectiive layer thrrough a single antibody--(TNF-α) binnding event (heere, q is the effective charge sensed by the transsistor, and thhe screeningg effect due tto the electricall double layer in solven nt has been involved i intoo q); NTNF iss the total nnumber of TN NF-α moleculees bound to the t HfO2 efffective layerr; CHfO2 is thhe total capaacitance of thhe HfO2 effeective layer. Th his ΔΦ inducces a changee in the cond ductive charrge (ΔQ=CHf he MoS2 chaannel. HfO2ΔΦ) in th This ΔQ can cause a shift of the threshold voltage (ΔVT) measured ffrom the bacck gate (notee: not measured d from the top t gate), and a ΔVT can n be evaluatted by ΔVT= =ΔQ/CSiO2=((CHfO2/CSiO2))ΔΦ= qN TNF , where CSiO22 is the capaacitance of th he back-gatee dielectric llayer. Furtheermore, NTNNF can C SiO 2
be calcullated using NTNF = σTNF A, A where σTNNF is the areaal density off bound TNF F-α moleculles on
3
the effective layer and A is the total sensor area. CSiO2 can be calculated using CSiO2 = kSiO2ε0A/dSiO2, where dSiO2 and kSiO2 are the thickness and dielectric constant of the SiO2 back-gate dielectric
VT
layer,
respectively;
ε0
is
the
vacuum
permittivity.
Therefore,
qN TNF qd SiO 2 TNF . C SifO 2 k SiO 2 0
4
Figure S3. S Linear-reegime sensor responses at the equiliibrium statee: The transffer characterristics of five different d MoS S2 transistorr sensors meeasured at vaarious biodeetection stagges, followinng the sequencee of (1) baree transistor, (2) antibod dy functionaalization, andd inputs of TNF-α soluutions with conccentrations of o (3) 60 fM M, (4) 300 fM M, (5) 600 fM M, (6) 3 pM, and (7) 6 pM M. The calibbrated linear-reg gime sensor responses from f these five f devices are plotted in Fig. 3 (bb) with respeect to TNF-α co oncentration n.
5
Figure S4. Subthreeshold-regim me sensor responses r aat the equilibrium statte: The traansfer characterristics of five different MoS M 2 transisstor sensors measured att various bioodetection sttages,
6
following g the sequen nce of (1) barre transistor,, (2) antiboddy functionallization, andd inputs of TN NF-α solutionss with concen ntrations of (3) 60 fM, (4) ( 300 fM, ((5) 600 fM, (6) 3 pM, annd (7) 6 pM M. The calibrated d subthresho old-regime sensor s respon nses from thhese five devvices are plootted in Fig. 4 (b) with resp pect to TNF--α concentrattion.
Figure S5. S A negativ ve control teest of the dettection speciificity of MooS2 transistorr biosensorss: The transfer characteristic c cs of a contrrol sensor measured m at sstages of (1)) bare transisstor, (2) antiibody functionaalization (stiill functionallized with an nti-human T TNF-α antiboody receptorrs), and inpuuts of IL-6 solu utions with concentration c ns of (3) 600 0 fM and (4) 6 pM.
7
Figure S6. S Transfer characteristiics of four different d Mo S2 transistorr biosensors measured bbefore the inputt of TNF-α samples, s from which thee subthreshoold-swing (SSS) parameteers were acqquired for norm malizing thee real-time subthreshold-regime seensor respoonses (Equaation (5)). T These sensors were w utilizeed to quantiify the real-time kinetiics of antibbody-(TNF-α α) binding uunder different TNF-α con ncentrations (n) of (a) 60 6 fM, (b) 600 fM, (c)) 3 pM, andd (d) 6 pM.. The n points (OP P, i.e., the fix xed VG and VDS values, under whicch a real-tim me response ccurve operation was meassured) are allso labelled by b the red arrrows.
8
Figure S7. S Sensor reesponses meaasured in thee subthreshoold regime of a MoS2 traansistor biosensor with a 60 0 nm thick HfO H 2 effectiive layer (i.ee., tHfO2 = 6 0 nm): (a) ttransfer charracteristics oof the MoS2 traansistor sensor with tHfO22 = 60 nm, which w were m measured froom a set of inncremental T TNFα concen ntrations (i.ee., n = 0, 60 fM, 300 fM, 600 fM M, 3 pM, annd 6 pM; (bb) The calibbrated subthresh hold-regime responses (S S) measured d from this ssensor (labellled as red sttars) with reespect to TNF-α α concentratiion (n). Thiss S-n relation nship measuured from thiis sensor witth tHfO2=60 nnm is consisten nt with thosee measured from f the sen nsors with tHHfO2 = 30 nm m. This resuult proves thaat the calibrated d sensor resp ponse valuess do not strongly dependd on the HfO O2 effective layer thickneess.
9
Hongsuk Nam1, †, Bo-Ram Oh1, †, Pengyu Chen1, Mikai Chen1, Sungjin Wi1, Wenjie Wan2, Katsuo Kurabayashi1, and Xiaogan Liang*,1 1 2
Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109
University of Michigan-Shanghai Jiao Tong University Joint Institute and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China
*Contact Email: [email protected] †
These authors contributed equally
Supporting Information
1
Figure S1. S Protoco ol for functiionalizing a MoS2 trannsistor senssor with antti-human TN NF-α antibody receptors fo or detecting TNF-α moleecules: (1) Im mmerse the HfO2-coatedd MoS2 transistor sensor in nto a 5% AP PTES solutio on and incub bate for 1 hoour. (2) Thee HfO2 surfaace silanizedd with APTES reacts r with a 5% solution n of glutaralldehyde (GA A) in phosphhate bufferedd saline (PBS S) for 2 hours, followed by y rinsing with PBS bufffer. (3) The HfO2 surface is then inncubated wiith an man TNF-α antibody a solution for 1 hour. (4) Thhe as-functiionalized sennsor is incubbated anti-hum with TN NF-α solution ns with inccremental co oncentrationns (2 hours for each cooncentrationn) for studying the sensor responses r att the equilib brium state aand the affinnity of the aantibody-(TN NF-α) pair, or the t device is subjected to a TNF-α α flow in a m microfluidicc channel forr quantifyinng the time-dependent assocciation/disso ociation kineetics of the anntibody-(TN NF-α) pair.
2
Figure S2. S The dual-gate thin-film transistorr biosensor m model: The binding of T TNF-α moleecules with the antibody reeceptors fun nctionalized on the HfO O2 effective layer can ccause a poteential change (Δ ΔΦ) on thiss effective laayer. ΔΦ caan be evaluaated using
qN TNF , where q iis the C HfO 2
effective charge brou ught to the HfO H 2 effectiive layer thrrough a single antibody--(TNF-α) binnding event (heere, q is the effective charge sensed by the transsistor, and thhe screeningg effect due tto the electricall double layer in solven nt has been involved i intoo q); NTNF iss the total nnumber of TN NF-α moleculees bound to the t HfO2 efffective layerr; CHfO2 is thhe total capaacitance of thhe HfO2 effeective layer. Th his ΔΦ inducces a changee in the cond ductive charrge (ΔQ=CHf he MoS2 chaannel. HfO2ΔΦ) in th This ΔQ can cause a shift of the threshold voltage (ΔVT) measured ffrom the bacck gate (notee: not measured d from the top t gate), and a ΔVT can n be evaluatted by ΔVT= =ΔQ/CSiO2=((CHfO2/CSiO2))ΔΦ= qN TNF , where CSiO22 is the capaacitance of th he back-gatee dielectric llayer. Furtheermore, NTNNF can C SiO 2
be calcullated using NTNF = σTNF A, A where σTNNF is the areaal density off bound TNF F-α moleculles on
3
the effective layer and A is the total sensor area. CSiO2 can be calculated using CSiO2 = kSiO2ε0A/dSiO2, where dSiO2 and kSiO2 are the thickness and dielectric constant of the SiO2 back-gate dielectric
VT
layer,
respectively;
ε0
is
the
vacuum
permittivity.
Therefore,
qN TNF qd SiO 2 TNF . C SifO 2 k SiO 2 0
4
Figure S3. S Linear-reegime sensor responses at the equiliibrium statee: The transffer characterristics of five different d MoS S2 transistorr sensors meeasured at vaarious biodeetection stagges, followinng the sequencee of (1) baree transistor, (2) antibod dy functionaalization, andd inputs of TNF-α soluutions with conccentrations of o (3) 60 fM M, (4) 300 fM M, (5) 600 fM M, (6) 3 pM, and (7) 6 pM M. The calibbrated linear-reg gime sensor responses from f these five f devices are plotted in Fig. 3 (bb) with respeect to TNF-α co oncentration n.
5
Figure S4. Subthreeshold-regim me sensor responses r aat the equilibrium statte: The traansfer characterristics of five different MoS M 2 transisstor sensors measured att various bioodetection sttages,
6
following g the sequen nce of (1) barre transistor,, (2) antiboddy functionallization, andd inputs of TN NF-α solutionss with concen ntrations of (3) 60 fM, (4) ( 300 fM, ((5) 600 fM, (6) 3 pM, annd (7) 6 pM M. The calibrated d subthresho old-regime sensor s respon nses from thhese five devvices are plootted in Fig. 4 (b) with resp pect to TNF--α concentrattion.
Figure S5. S A negativ ve control teest of the dettection speciificity of MooS2 transistorr biosensorss: The transfer characteristic c cs of a contrrol sensor measured m at sstages of (1)) bare transisstor, (2) antiibody functionaalization (stiill functionallized with an nti-human T TNF-α antiboody receptorrs), and inpuuts of IL-6 solu utions with concentration c ns of (3) 600 0 fM and (4) 6 pM.
7
Figure S6. S Transfer characteristiics of four different d Mo S2 transistorr biosensors measured bbefore the inputt of TNF-α samples, s from which thee subthreshoold-swing (SSS) parameteers were acqquired for norm malizing thee real-time subthreshold-regime seensor respoonses (Equaation (5)). T These sensors were w utilizeed to quantiify the real-time kinetiics of antibbody-(TNF-α α) binding uunder different TNF-α con ncentrations (n) of (a) 60 6 fM, (b) 600 fM, (c)) 3 pM, andd (d) 6 pM.. The n points (OP P, i.e., the fix xed VG and VDS values, under whicch a real-tim me response ccurve operation was meassured) are allso labelled by b the red arrrows.
8
Figure S7. S Sensor reesponses meaasured in thee subthreshoold regime of a MoS2 traansistor biosensor with a 60 0 nm thick HfO H 2 effectiive layer (i.ee., tHfO2 = 6 0 nm): (a) ttransfer charracteristics oof the MoS2 traansistor sensor with tHfO22 = 60 nm, which w were m measured froom a set of inncremental T TNFα concen ntrations (i.ee., n = 0, 60 fM, 300 fM, 600 fM M, 3 pM, annd 6 pM; (bb) The calibbrated subthresh hold-regime responses (S S) measured d from this ssensor (labellled as red sttars) with reespect to TNF-α α concentratiion (n). Thiss S-n relation nship measuured from thiis sensor witth tHfO2=60 nnm is consisten nt with thosee measured from f the sen nsors with tHHfO2 = 30 nm m. This resuult proves thaat the calibrated d sensor resp ponse valuess do not strongly dependd on the HfO O2 effective layer thickneess.
9
