ngModel with variable value

Question

Use Ionic 2, I need ngmodel to have a value of a class variable, but error when placing in view, follow my code: viiew

<ion-navbar *navbar>
  <ion-title>
    POSimplex
  </ion-title>
</ion-navbar>

<ion-content class="home" padding>
  <button ion-button full (click) = "teste()">Login</button>
  <p>
    <button ion-button full (click) = "addInput()">Criar conta</button>
  </p>



  <ion-list>
    <ion-item *ngFor="let item of inputs">
            <ion-label fixed>{{item.title}}</ion-label>
            <ion-input type="{{item.type}}" value="{{item.value}}" [(ngModel)] = "{{item.model}}"></ion-input>
        </ion-item>
</ion-list>


</ion-content>

ts :

import {Component} from "@angular/core";
import {NavController, Alert} from 'ionic-angular';


@Component({
  templateUrl: 'build/pages/home/home.html'
})
export class HomePage {

  inputs: Array<{title: string, type: string, value: any, model: string}>;
  inputsList: Array<Array<{title: string}>>;
  sl:string

  constructor(private navController: NavController) {
    this.inputsList = [];
    this.inputs = [
              {title: 'User Name', type: 'text', value: 'Fulano de tal', model: 'sl'},
              {title: 'Price', type: 'text', value: 500, model: 'sl'}
          ];
  }

  addInput() {
      //this.inputs.push({ title: "teste", type: "text", value: "valor" });
  }

  teste() {
    let alert = Alert.create({
      title:'teste',
      message:'msg'+this.sl
    });
    this.navController.present(alert)
  }


}

Console error : browser_adapter.js:77EXCEPTION: Error: Uncaught (in Promise): Template parse errors: Parser Error: Got Interpolation ({}}) Where Expression was expected at column 0 in [{{item.model}}] in Homepage@17:67 ("Fixed>{{item.title}} ][(ngModel)] = "{item.model}}"> "): Homepage@17:67 Parser Error: Got Interpolation ({}}) Where Expression was expected at column 0 in [{{item.model}}=$Event] in Homepage@17:67 ("Fixed>{{item.title}} ][(ngModel)] = "{item.model}}"> "): Homepage@17:67

How can I solve ?