Invalid path

Ionic Framework ionic-v3
1

import { Injectable } from ‘@angular/core’;

import {AngularFireDatabase, AngularFireObject} from “angularfire2/database”;
import { User } from ‘firebase/app’;
import { Profile } from ‘…/…/models/profile/profile.interface’;

@Injectable()
export class DataProvider {

profileObject: AngularFireObject;

constructor(public database: AngularFireDatabase) {

}

async saveProfile(user: User, profile: Profile){

    this.profileObject = this.database.object('/profiles/${user.uid}');

    try {
     await this.profileObject.set(profile);
     return true;
    }
    catch (e){
      console.error(e);
      return false;
    }

  }

}

import { Component } from ‘@angular/core’;
import { Profile } from ‘…/…/models/profile/profile.interface’;
import { DataProvider } from ‘…/…/providers/data/data’;
import { AuthProvider } from ‘…/…/providers/auth/auth’;
import { Subscription } from ‘rxjs/Subscription’;
import { User } from ‘firebase/app’;
@Component({
selector: ‘app-edit-profile-form’,
templateUrl: ‘edit-profile-form.html’
})
export class EditProfileFormComponent {

private authenticatedUser$: Subscription;
private authenticatedUser: User;
profile={} as Profile;

constructor(private data: DataProvider, private auth: AuthProvider) {
this.authenticatedUser$ = this.auth.getAuthenticatedUser().subscribe((user: User)=>
{
this.authenticatedUser= user;
})
}

async saveProfile(){
if (this.authenticatedUser) {
const result = await this.data.saveProfile(this.authenticatedUser,this.profile);
console.log(result);
}
}

}

when click on save button this error shows up

ERROR:
Error: Uncaught (in promise): Error: Reference.child failed: First argument was an invalid path = “/profiles/${user.uid}”. Paths must be non-empty strings and can’t contain “.”, “#”, “$”, “[”, or "]"
Error: Reference.child failed: First argument was an invalid path = “/profiles/${user.uid}”. Paths must be non-empty strings and can’t contain “.”, “#”, “$”, “[”, or “]”